Vol.:(0123456789) Educational Assessment, Evaluation and Accountability https://doi.org/10.1007/s11092-025-09460-1 Collaboration on school improvement under different educational accountability systems in two countries Andrea Wullschleger1   · Alan J. Daly2   · Nicolette van Halem3   · Katharina Maag Merki4   · Beat Rechsteiner4  Received: 12 January 2024 / Accepted: 20 June 2025 © The Author(s) 2025 Abstract Schools must continuously improve their practices to address today’s societal chal- lenges. To advance school improvement, educational accountability systems have been implemented in many parts of the world; they vary significantly in the levels of pressure they exert on schools. Given that school improvement is inherently a social and complex collaborative process, this paper delves deeper into how collaboration within school teams on improvement efforts varies across different accountability systems, considering social network data of school teams for the first time. Primary, key elements of accountability systems are analyzed theoretically to better under- stand the relationship between educational accountability systems and collaboration on school improvement. Taking an exploratory binational approach, the paper then compares a more bureaucratic and legal accountability system, operating as a high- stakes approach, in a school district in a city in California, USA, and a more profes- sional accountability system, operating as a low-stakes approach, in a school com- munity in a canton in the German-speaking part of Switzerland. The main focus of the comparative analyses is on key elements of the social network structure of staff members of elementary schools and central conditions of collaboration on school improvement, namely, trust relations and leadership. The findings provide initial evidence for a more positive relationship between collaboration on school improve- ment, social cohesion, and trust in a system that focuses on professional account- ability than in a system that focuses on bureaucratic and legal accountability. There are no accountability-specific differences in the network position of leaders in this comparison, however. The findings suggest that the assumptions are worth pursuing further in future research. Keywords  Accountability systems · School improvement · Collaboration in school teams · Trust · Leadership Extended author information available on the last page of the article http://orcid.org/0000-0003-4390-3835 http://orcid.org/0000-0002-6760-8374 http://orcid.org/0000-0001-8155-7254 http://orcid.org/0000-0002-0215-1684 http://orcid.org/0000-0003-2555-431X http://crossmark.crossref.org/dialog/?doi=10.1007/s11092-025-09460-1&domain=pdf Educational Assessment, Evaluation and Accountability With society undergoing rapid transformations in an increasingly complex, vola- tile, and uncertain world, the current educational landscape faces many challenges. It must respond swiftly to changes, such as technological innovations or migration, develop effective pathways for inclusion and equity for an increasingly diverse stu- dent body, provide professional development for a variety of actors, and continually enhance the quality of education. To effectively address these challenges, schools must be able to constantly improve their practices, meaning that schools must be capable of managing change and adapting to new situations and requirements (Hop- kins, 2005). Accordingly, the schools’ capacity for school improvement is heavily relevant for the further development of educational systems. School improvement as “a distinct approach to educational change that enhances student outcomes as well as strengthening the school’s capacity for managing change” (Hopkins, 2005, p. 3) is deeply rooted in collaboration among members of the school team (García-Martínez et al., 2021; Nguyen & Ng, 2020). To achieve shared goals for school improvement and make joint decisions along the way, school team members work and learn together through intensive and ongoing negotiation and discourse (Mitchell & Sackney, 2011). Accordingly, school improvement is strongly socially constructed (Daly, 2010). The individual school represents the focal point for improving its practices, but it does not operate in isolation. A school is embedded within an educational system that influences the school’s actions. School improvement, as a systematic process of advancing the practices of individual schools, is thus regarded as part of the overall educational system (Emmerich & Maag Merki, 2014; Maag Merki, 2021; Hopkins, 2005). In many countries, school improvement is mandatory for schools. It is seen as a means to improve the quality of teaching and learning, taking into account the goals and standards set by school authorities. Furthermore, educational accountability systems have been introduced in many parts of the world (UNE- SCO, 2017/8; O’Day, 2002) to advance school improvement. These school-ori- ented accountability systems aim to improve student learning by enhancing the functioning of the school organization. Previous studies provide evidence that accountability systems around the globe vary (UNESCO, 2017/8; O’Day, 2002) and that they influence the educational practices in schools (e.g., Altrichter & Kemethofer, 2015; Coburn et al., 2016; Penninckx, 2017). However, very little is known so far about the relationship between different accountability systems and school improvement in individual schools by focus- ing on how school teams collaborate on school improvement (Coburn & Russell, 2008). The overarching aim of this paper is therefore to advance the understand- ing of variations in collaborative school improvement processes among school teams across two distinct educational accountability systems. We compared school improvement in one state in the USA, which is characterized by high accountability pressures, and in one canton (state) in Switzerland, which exerts little accountability pressure on schools. We examined to what extent differences in key elements of the structure of collaboration networks focused on school improvement and differences in central conditions of collaboration on school improvement manifest in these two different educational accountability systems. Educational Assessment, Evaluation and Accountability This study contributes to extending current knowledge on how collaboration within school teams is structured and enacted in different educational accountabil- ity systems. Building on already existing frameworks (Maag Merki, 2016; Darling- Hammond, 2004; O’Day, 2002), we developed and carried out a preliminary exami- nation of assumptions by conducting a small-scale exploratory case study aimed at gathering initial evidence that could then be tested in future larger scale studies. The paper is organized as follows: First, from a theoretical perspective, we focus on key elements of accountability systems and their role in school improvement. We provide a detailed description of the two accountability systems examined in this study, a bureaucratic and legal accountability system and a more professional accountability system, and discuss how types of accountability systems are related to school improvement. In a second step, we discuss school improvement as a social and collaborative process within school teams. Following this, we review the state of research on the relationship between different accountability systems and collabo- ration on school improvement and formulate assumptions for further exploration of this relationship. We then investigate mechanisms of how the accountability systems are related to social interaction patterns among school staff members by referring to two contrasting cases, providing a comprehensive method section and a detailed presentation of results. Finally, we discuss the findings of the case study in relation to the theoretical assumptions. 1 � Accountability systems and their role in school improvement To enhance school improvement in individual schools, educational accountabil- ity systems have been implemented in many regions worldwide (O’Day, 2002; UNESCO, 2017). However, there are varying approaches to applying account- ability pressure on schools to foster their improvement. Building on Hamilton et al. (2008), Klieme (2004), and Maag Merki (2016), the functioning of school-based accountability for school improvement, on a general level, can be described as fol- lows: External input from the macro level of the education system—such as edu- cational standards and curricula provided through governmental administration and policies—serve to establish expectations for schools. This input initiates processes within schools, which in turn generate output in terms of student learning. In many countries, there are two possible ways to verify whether the expectations placed on schools via input are being met: Processes within schools can be monitored through external school inspections (and sometimes by requiring schools to monitor their own quality), and output of schools can be assessed as student learning performance at the schools by standardized tests and final examinations. Both approaches facilitate a comparison of actual state (school processes or outcomes) and expected state by aligning the school processes or the school output with the established expectations. When the comparison between actual and target reveals significant gaps, appropriate measures for school improve- ment are undertaken, guided by the framework of the existing accountabil- ity system. Accountability systems typically encompass tools and processes designed to ensure that people, groups, organizations, and institutions fulfill their Educational Assessment, Evaluation and Accountability responsibilities (Hatch, 2013). Many education systems diverge at this point, adopting varying approaches to exerting accountability pressures on schools to promote their improvement. There are various theoretical approaches to distinguishing differences in accountability pressures on schools. A widely recognized framework by Darling- Hammond (2004) identifies several types of educational accountability: political, legal, bureaucratic, professional, and market. Darling-Hammond explains that rarely does only one form of accountability operate in a given area: “The choices of accountability tools – and the balance among different forms of accountability – are constantly shifting as problems emerge, as social goals change, and as new circumstances arise” (p. 8). However, Darling-Hammond observes that legal and bureaucratic accountability tends to dominate most urban public school systems in the USA. In contrast, public school systems in Switzerland are more commonly associated with professional accountability (SCCRE, 2023, p. 31). A detailed description of these two types of accountability is provided in the following. Bureaucratic accountability refers to federal, state, and district agencies defin- ing rules and regulations that are intended to govern the actions of schools and their actors, and legal accountability emphasizes adherence to laws, allowing citizens to seek judicial remedies when public schools are perceived to violate legal provisions. Bureaucratic and legal accountability often converge in efforts to standardize educational practices; this creates a framework governed by pre- scribed curricula and test-based accountability mechanisms (Darling-Hammond, 2004). In many cases, this kind of accountability tends to be high-stakes, mean- ing that discrepancies between actual and target performance are met with sanc- tions. It assumes that rewards and sanctions emanating from government policy have a direct and strong influence on the actions of teachers and schools (Dia- mond, 2012). Large discrepancies between actual and target are strongly sanc- tioned (Hamilton et al., 2008). In professional accountability, school staff are expected to continuously pro- fessionalize and align their work with professional standards (Darling-Hammond, 2004). Schools and their actors are perceived as capable of reflecting on discrep- ancies and of deriving appropriate improvement measures if large discrepancies between actual and target occur (Hamilton et  al., 2008). Accordingly, this type of accountability is predominantly low-stakes, as consequences are not based on sanctions. Hatch (2013) suggests that bureaucratic and legal accountability systems, which often impose high-stakes consequences, primarily aim to establish answer- ability, whereas professional accountability systems focus on fostering respon- sibility. Answerability involves holding individuals and groups accountable for adhering to specific procedures or achieving agreed-upon goals. Responsibility, on the other hand, emphasizes accountability for upholding norms of conduct and broader purposes, which are often more abstract and less explicitly defined. In the next sections, we examine in greater detail the two approaches— standardized tests and school inspections—to verifying whether the expec- tations placed on schools are being met in relation to the described types of accountability. Educational Assessment, Evaluation and Accountability 1.1 � Standardized tests and school improvement Standardized tests are often discussed in connection with bureaucratic account- ability. In the USA, this approach is most readily associated with the No Child Left Behind Act of 2001 and subsequent accountability policy levers. To respond to achievement gaps, many US states implemented increased standardized test- ing coupled with a reward and sanction system (Darling-Hammond, 2004). This accountability is tied to student performance on yearly externally mandated tests, and after the No Child Left Behind Act, states began to more aggressively publish testing results (Coburn et al., 2016). Failure to achieve the targets led to the clas- sification “in need of improvement” and resulted in progressive sanctions (Daly et  al., 2011). This kind of accountability leads to a strong focus on compliance with external measures and to an orientation toward improving test results rather than teaching and learning (Datnow et al., 2020). Research on the impact of this kind of high-stakes accountability has found that it has influenced the development of practices in districts, schools, and class- rooms, although not always as intended and oftentimes with detrimental effects (Daly et  al., 2014; Coburn et  al., 2016). Negative effects include, for instance, inflexibility in acting, narrowed focus on established processes, lower job satis- faction, inability to solve problems creatively, or increased conflict (Daly et al., 2011; Maag Merki, 2016). 1.2 � School inspections and school improvement School inspections focus on school processes, such as the school climate, col- laboration, or instructional quality, and include at least one site visit to assess whether the schools meet quality standards (Hofer et al., 2020; Penninckx, 2017). Most of the research on school inspections is found in the European context. In Europe, schools have been increasingly granted more autonomy in procedures, which has led to a heightened necessity to ensure their accountability for quality (OECD, 2013). Further, the rationale behind inspections rests on the presumption that they facilitate school improvement (Penninckx & Vanhoof, 2015). School inspections are associated with different types of accountability. Altrichter and Kemethofer (2015) investigated varying levels of accountability pressure through school inspections, the impact on improvement activities, and unintended effects in seven European countries. They found that higher account- ability pressure (closer to bureaucratic and legal accountability) through school inspections is related to more improvement activities in schools than lower accountability pressure (closer to professional accountability) is but at the same time results in more unintended consequences. Ehren et  al. (2015) additionally focused on the processes of different school inspection systems and their impact and found that the most effective inspectorates are those that conduct cyclical and additional visits depending on the inspection outcomes, assess process elements and school outcomes, and make each school’s results public. However, these Educational Assessment, Evaluation and Accountability types of inspections also lead to unintended consequences, such as narrowing of the curriculum or less experimentation with new teaching methods. 2 � Two accountability systems in contrast In this study, the focus is on two locations that are embedded in highly distinct accountability systems: a school district in a city in the US state of California and a school community in a canton in the German-speaking part of Switzerland. To provide a basis for further elaboration, the characteristics of these two locations and their accountability systems are described in the following. 2.1 � Accountability system in the USA and more specifically in California In 2015, the Every Student Succeeds Act replaced the No Child Left Behind Act; this resulted in a somewhat broader view of accountability (Datnow et  al., 2020). Further, state-led efforts to develop the Common Core State Standards (CCSS) were initiated in 2009. The CCSS establish guidelines for what every student should know and be able to do in mathematics and English language arts from kinder- garten through Grade 12. California has made several educational policy changes, including adopting the new curriculum standards, adapting approaches to funding and accountability, and moving toward a more decentralized governmental model (Loeb et al., 2018). The system can be considered hierarchical in that strong rules are given, but they can be realized in different ways (Datnow et al., 2022). Accountability is still focused on student achievement results coupled with a high level of transparency, in that test data is made publicly available. In California, English language arts/literacy, mathematics, science, and optional Spanish language arts are assessed yearly. The results for each school on each test are available online (CAASPP, 2021; California School Dashboard, 2017). This test-based account- ability system is aligned with compliance with the performance standards set by external agencies (CCSSI, 2022). Further, schools must produce a School Account- ability Report Card annually to provide information to the community, including demographic data, climate for learning information, or school completion rates. The purpose is a public comparison of schools on student achievement, environment, resources, and demographics (SARC, 2022). With reference to the accountability approaches described above, it becomes evident that California sets expectations through educational standards and evalu- ates the achievement of these standards based on school output using standardized tests (Maag Merki, 2016). When discrepancies arise between actual and target, the California system leans heavily on what Darling-Hammond (2004) referred to as bureaucratic and legal accountability, operating as a high-stakes approach (Dia- mond, 2012). This approach exerts significant pressure on schools through rigorous testing, public reporting of testing results, and sanctions on schools that fail to meet the established targets. Educational Assessment, Evaluation and Accountability 2.2 � Accountability system in Switzerland and more specifically in the canton of interest Since 2006 the Swiss cantons have been obliged to harmonize important goals and structures of compulsory education, such as enrollment, duration of education lev- els, and educational goals (EDK, 2011). This led to the formulation of national edu- cational standards starting in 2011. The standards described basic competencies for students in the school language, foreign languages, mathematics, and science by the end of Grades 4, 8, and 11. The standards were subsequently integrated into new curricula and have been reviewed on a sample basis since 2016 (EDK, 2022; ÜGK, 2022). The results of these reviews are publicly presented on a national level only and not on a school level. In addition, performance assessments for students take place in individual regions in Switzerland. In the canton in which the schools in this study are located (in the German-speaking part of Switzerland), at the time of the study, no regular, area- wide standardized tests were conducted at elementary schools. There are cantonal school inspections during which the schools are evaluated every three to five years. The schools receive a professional external review, related to cantonal quality stand- ards. This is a formative evaluation for the attention of the respective school only. The evaluation is not made available to the public, and there are no consequences for the schools. With reference to the accountability approaches described above, it becomes evi- dent that like California, the Swiss canton examined here sets expectations through educational standards; however, it evaluates the achievement of these standards based on monitoring the school processes through school inspections. When dis- crepancies arise between actual and target, the cantonal system leans strongly on what Darling-Hammond (2004) referred to as professional accountability, operat- ing as a low-stakes approach (Diamond, 2012). This approach puts no pressure on schools. There is no standardized testing. And school inspections are formative, as schools face no sanctions or high-stakes consequences. The preceding exploration argues that accountability systems in many parts of the world aim to promote school improvement. These school-based accountability systems seek to enhance student learning by enhancing the functioning of school organizations (O’Day, 2002). Accordingly, the next section delves deeper into the concept of school improvement. 3 � School improvement as a social and collaborative process in school teams When we speak of school improvement, we refer to Hopkins (2005, p. 3), who defines it as “a distinct approach to educational change that enhances student out- comes as well as strengthening the school’s capacity for managing change.” School improvement is understood as an inherently social, often informal, and complex collaborative process (Daly, 2010). Collaboration in school teams (including teach- ers, specialist teachers, and principals) is a driving force of school improvement. Educational Assessment, Evaluation and Accountability Continuous school improvement is only achievable through purposeful and effective collaboration (García-Martínez et  al., 2021; Muckenthaler et  al., 2020; Nguyen & Ng, 2020; Weddle et al., 2020). Collaboration and school improvement are deeply joined, in that to achieve shared goals for school improvement and make joint deci- sions along the way, school team members interact by working and learning together through intensive and ongoing negotiation and discourse (Mitchell & Sackney, 2011). This paper focuses specifically on collaboration within school teams where new ideas for the improvement of the school are discussed. Accordingly, these are interactions in which active and joint consideration is given to the further develop- ment of the school. Collaboration refers to job-related social interactions among staff members, that is, their actual joint actions to carry out their profession (Kelchtermans, 2006). Van- grieken et al., (2015, p. 23) define collaboration as “joint interaction in the group in all activities that are needed to perform a shared task.” From a social network perspective, interactions between actors are crucial because they provide opportuni- ties for social capital transactions (Daly, 2010; Coburn & Russell, 2008; Moolenaar, 2012). This claim is grounded in theories on social capital, which have two perspec- tives (Coppe et al., 2022): a more individual perspective describing interactions as social ties that provide indirect access to the resources and expertise of all the other individuals someone is connected to (Bourdieu, 1986), and a more social perspec- tive describing interactions in a group as social cohesion fostering trust, support, or solidarity (Coleman, 1990). It is assumed that collaboration in school teams is an effective way for schools to build a professional culture and for teachers to develop professionally, thereby improving the quality of teaching as well as student learning (García-Martínez et al., 2021; Nguyen & Ng, 2020; Spillane & Louis, 2002). However, not every collabora- tion automatically leads to improved student learning. The conditions under which collaboration takes place and the quality of collaboration are crucial for its effective- ness (Graham, 2007; Ronfeldt et al., 2015). Regarding conditions supporting collaboration on school improvement, the following section looks at trust relations and leadership as two central build- ing blocks (Ehren & Baxter, 2021) as well as at social network structures that shape the quality of teacher collaboration on school improvement. The focus is on interactions in social networks that are about exploring new ideas for school improvement. 3.1 � Trust as a prime resource for collaboration on school improvement High levels of trust in schools may result in more candid and effective forms of col- laboration on school improvement (Brown et  al., 2015; Tschannen-Moran, 2014), because trust motivates the sharing of information in social interactions and leads to improved school quality and student outcomes (Bryk & Schneider, 2002; Coburn & Russell, 2008; Ehren & Baxter, 2021). Trust is defined as “an individual’s or group’s willingness to be vulnerable to another party based on the confidence that the latter party is benevolent, reliable, competent, honest, and open” (Hoy & Educational Assessment, Evaluation and Accountability Tschannen-Moran, 2003, p. 186). The act of making oneself vulnerable to others is a powerful social resource that supports collaboration, reflective dialogue, and the opening up of practice. Trust and collaboration are closely tied together because, especially for collabo- rative processes on school improvement, there is little willingness to share critical information or to implement innovations if trust is missing. This limits teacher and team development and effectiveness. When trust is present, cooperative behaviors such as personal engagement, sharing information, and relying on other team mem- bers are more likely (Moolenaar et al., 2014; Hallam et al., 2015; Tschannen-Moran, 2001). In a trusting environment, school teams are more confident about trying new things without fear of failure (Moolenaar & Sleegers, 2010). 3.2 � (Collective) leadership as a prime resource for collaboration on school improvement Leadership also emerges as a key condition for teacher collaboration on school improvement (García-Martinez et  al., 2021). Research studies have confirmed the role of school leadership (e.g., Robinson et al., 2008), middle leadership (e.g., Bry- ant et  al., 2020), and teacher leadership (e.g., Nguyen et  al., 2019) in promoting professional learning communities. School leaders play an important role in creating and articulating conditions that foster collaboration. They can improve the quality of collaboration by organizational design. In turn, fostering collaboration helps trans- form schools (Hallinger & Liu, 2016; Wahlstrom & Louis, 2008). In this regard, col- lective or distributed leadership is particularly important (Amels et al., 2020; Penuel et al., 2010). According to Harris (2003, p. 322), “if we are serious about building professional learning communities within and between schools then we need forms of leadership that support and nourish meaningful collaboration among teachers.” Distributed leadership has an impact on teachers’ motivation, commitment, profes- sional learning, and collaboration (Amels et al., 2020). This in turn influences the improvement of not only teaching but also student achievement (Hendriks & Steen, 2012; Louis et al., 2010). 3.3 � Social network structures as key elements of quality collaboration on school improvement Research suggests that the structure of networks, including density, reciprocity, cen- trality, centralization, and transitivity, provides insights into the quality of collec- tive implementation of reforms and innovations, particularly because relationships among individuals provide opportunities for social capital transactions (Coburn & Russell, 2008). Density indicates the activity or level of communication of individu- als in the network (Robins, 2015). In the context of school improvement, density provides information on the extent to which the social structure in schools allows for the exchange, sharing, and adaptation of, for example, knowledge (Moolenaar, 2012). A higher number of connections facilitates the implementation of school improvement, because more opportunities to discuss matters concerning school Educational Assessment, Evaluation and Accountability improvement enable mutual sense-making, co-construction, collective learning, or shared understanding (Daly, 2010). Reciprocity quantifies the extent of mutual relationships and provides the basis for more intensive exchange. This is because mutual relationships reflect higher trust and support the transfer of deeper knowledge (Hubers et al., 2017). Centrality indicates how important an actor is in a network. An actor’s degree centrality is the number of incoming relationships (indegree), which stands for the prestige of a person, and the number of outgoing relationships (outdegree), which stands for active “reaching out to someone” (Fuhse, 2016). An actor’s “degree” pro- vides information on the extent to which an actor in a school has access to talking about innovations with others and what status they enjoy in terms of discussing new ideas for school improvement (Brandes et al., 2012). Further, actors can be central in terms of how often they are on the shortest paths between other actors in the net- work (betweenness centrality) (Freeman, 1978). This illustrates the extent to which actors in a school have control over the flow of information and thus the diffusion of new ideas within the school team (Brandes et al., 2012). Whereas centrality refers to the influence of individual participants within a net- work, centralization is about the network. The interaction patterns in the entire net- work are assessed on a continuum between “all actors are equally central” (decen- tralized network) and “one actor exhibits maximum centrality” (centralized network) (De Lima, 2010). In a highly centralized team, members with a central position contribute heavily to decisions, regardless of whether they are qualified or formally legitimized to do so. These actors thus have a (disproportionately) high influence in a network (Hubers et al., 2017). Transitivity provides an impression of the strength of the relationships. The fol- lowing is assumed: If person A and person B as well as person A and person C are connected, the probability is high that a relationship also exists between person B and C (Granovetter, 1973). To get an idea of relationship strength, the focus is on the proportion of closed triads in the network. Transitivity indicates the presence of strong relationships, in our case when discussing school improvement matters. According to Coleman (1990), many strong relationships represent social cohesion, which makes it almost impossible not to cooperate, not to offer support, or not to trust each other. 4 � State of research: the relationship between different accountability systems and collaboration on school improvement The relationship between accountability systems and teacher collaboration is under- studied. In one of the few studies available in this area, Coburn and Russell (2008) investigated the link between district policies and teacher collaboration regarding the implementation of reforms and innovations in elementary schools in two dis- tricts. They focused on four dimensions: structure of ties, access to expertise, trust, and content of interactions. They found that district policy can influence network structure, access to expertise, and the depths of interactions, all of which provide opportunities for effective collaboration on school improvement. Also, their findings Educational Assessment, Evaluation and Accountability pointed to the important role of school leaders in mediating district policy in both constraining and intensifying district efforts. They revealed that school leaders influ- enced the frequency and depth of interaction in school teams. However, Coburn and Russell focused more on the mediating role of school leaders than on the role of school leaders in different districts. Further, regarding trust in school teams, they found that trust relations differed more within schools than between schools. Coburn and Russell (2008) examined the relationship between district policy and collaboration in schools within the same country and the same state. Already at this level, they found differences in the relationship between educational policies and col- laboration. However, we believe that with an international perspective on account- ability systems with significantly greater differences, further and deeper insights on this relationship can be found. This might also be the case when analyzing the role of school leaders. As Coburn and Russell focused only little on differences in school leadership in the districts and did not find between-school differences in trust, it is important to delve deeper into the question of how they are related to the type of accountability systems, as school leadership and trust are regarded as highly relevant for teacher collaboration. 5 � Aim, research questions, and assumptions on collaboration on school improvement under different educational accountability systems The aim of our binational comparative study was to analyze social network struc- tures of school teams as well as trust relations and leadership in schools as core elements of the quality of collaboration on school improvement in two very differ- ent accountability systems. It was not our goal to produce generalizable findings for a wider population. We aimed instead to contribute to an evolving theory on the relationship between accountability systems and teachers’ collaboration on school improvement. This contribution might serve as a foundation for future investigations delving into causal relationships. This exploratory case study was guided by the following research questions: 1. To what extent do differences in social network structures related to the quality of collaboration on school improvement manifest within the context of bureaucratic and legal accountability versus the context of professional accountability? 2. To what extent are there differences in trust relations and leadership as two central conditions of collaboration on school improvement within the context of bureau- cratic and legal accountability versus the context of professional accountability? As there is limited research on the relationship between accountability sys- tems and collaboration on school improvement, we formulated several assump- tions based on theoretical considerations presented in the section above. The argument was that education systems respond differently to discrepancies between expectations set at the macro level of the education system and the Educational Assessment, Evaluation and Accountability actual state of school processes or school outcomes depending on types or levels of accountability pressures with the aim to advance school improvement. In a bureaucratic and legal accountability system that tends to impose high-stakes consequences, schools may approach discrepancy based more on answerability (Hatch, 2013) and follow a certain hierarchy to implement what is expected of them. Accordingly, we assumed that collaboration networks on school improvement are more centralized. Further, we assumed that a lower level of collaboration on school improvement may occur, meaning less dense networks with fewer opportunities and therefore less access to discussing school improvement with others. In addition, we assumed that there was lower strength of the relationships and thus less social cohesion as reflected by transitivity in a bureaucratic and legal accountability system. In contrast, in a professional accountability system that tends to be low- stakes, the response to discrepancy may be based more on responsibility (Hatch, 2013), which we assumed may lead to shared responsibility and therefore decen- tralized networks. We further assumed that there is more intensive collabora- tion, reflected in more dense networks, providing more opportunities to discuss school improvement. Related to this, we assumed that there are stronger rela- tionships and stronger social cohesion within the school team to address change in a professional accountability system. In these complex dependencies, trust and school leaders play an important role. According to Cerna (2014), trust is key for policy making. In the field of education, trust is particularly central to the implementation of innovations because it can decrease uncertainty about change. High-stakes external control that may be imposed in bureaucratic and legal accountability often leads to the destruction of trust and an increase in policies and procedures, whereas a more professional accountability system with a low-stakes approach may improve trust (Daly, 2009; Ehren & Baxter, 2021). Therefore, we assumed that there is less trust in relationships in a bureaucratic and legal accountability system than in a professional accountability system. School leaders have an important role in mediating state and district policy advanced at the macro level to the micro level, as they are the connectors, the intermediaries, between policy and teachers (Spillane et al., 2002). School lead- ers may alternately pause or intensify the district’s efforts to develop professional communities of teachers at the school site (Camburn et al., 2008). Spillane and Anderson (2019) explained that “how school leaders come to understand policy can influence teachers’ sense-making, as school leaders work to focus teachers’ attention on some aspects of policy rather than others” (p. 123). Therefore, we assumed that persons in leadership positions are central actors in both account- ability systems but in a different way. We assumed that in bureaucratic and legal accountability systems, the school teams are more focused on persons in leader- ship positions leading the way of improvement, whereas professional account- ability systems are more likely to adhere to a distributed leadership approach, walking the path to improvement together. Educational Assessment, Evaluation and Accountability 6 � Method This study followed a social network approach. Social networks are particularly well-suited for the investigation of teacher collaboration. Social network analysis makes it possible to examine how individuals interact in a social context (Was- serman & Faust, 1994). The value of social network analysis for studying teacher collaboration lies in “its considerable theoretical base as well as its rigorous methodology, which provides the ability to visualize and analyze teacher inter- actions and make teacher collaboration more tangible” (Moolenaar, 2012, pp. 31–32). 6.1 � Participants and procedure To answer our research questions, we intentionally chose very different account- ability systems (see section “Two Accountability Systems in Contrast” above). We focused on two locations that are embedded in highly distinct accountability systems: a school district in a city in the US state of California and a school community in a canton in the German-speaking part of Switzerland. Data for this paper were drawn from two larger studies, one examining school improve- ment in California and one examining school improvement in German-speaking Switzerland. We followed a purposive sampling strategy (Campbell et al., 2020). To ensure comparability across the very different systems, we chose regions and schools that were very similar. At the region level, we compared a district in California with a municipality in Switzerland, both of which had a large majority of wealthy residents. At the school level, we looked for schools that were strongly similar in the following aspects: size, team structures and team seniority, high school qual- ity (excellent schools), and located in an environment with high socioeconomic status. Participants were 124 staff members (principals, teachers, specialist teach- ers) at two elementary schools in a school district in California and two elemen- tary schools in a municipality of a canton (state) in the German-speaking part of Switzerland (Table 1). Table 1   Characteristics of the participating schools CH = Switzerland. School Country Nstaff Nleading Response rate (%) Women Seniority (years) M (SD) Min Max 1 CH 29 4 86.2 25 (86%) 20.3 (12.3) 0 42 2 CH 34 8 88.2 29 (85%) 18.9 (9.8) 1 40 3 USA 27 8 88.9 22 (81%) 18.8 (9.6) 3 35 4 USA 34 10 85.3 30 (88%) 17.9 (8.9) 1 35 Educational Assessment, Evaluation and Accountability 6.2 � Measures To analyze collaboration on school improvement, we examined an instrumen- tal social network. Instrumental networks are about the flow of information and resources (Finnigan & Daly, 2010). Two slightly different questions were asked at the schools in California (“With whom do you explore new ideas for the overall improvement of your school?”) and at the schools in Switzerland (“With whom have you discussed the improvement of your school in the last 6  months?”). This dif- ference came about because the network questions were integrated in two different studies and had to be located in the language and context of each. However, the target of the interaction, namely, the focus on improvement of their school, was the same. Participants were given a list of all members of their school team from which they could select interaction partners. To analyze trust, we examined an expressive social network. Expressive networks are about affective relationships (Finnigan & Daly, 2010). Also here, two slightly different questions were asked at the schools in California (“With whom do you have a close relationship? By close relationship we mean a person with whom you candidly share personal information”) and at the schools in Switzerland (“To whom do you entrust something personal?”). In addi- tion, principals were asked about the leadership roles of all team members. 6.3 � Analytic approach To answer the first research question, on differences and similarities in the struc- ture of collaboration networks on school improvement, network measures of the instrumental network were computed at both the school and individual levels (see Table 2 and section “Social Network Structures as Key Elements of Quality Col- laboration on School Improvement” above). To answer the second research question, on the central conditions of trust relations and leadership, there were three analysis steps: (1) We analyzed the trust network by computing network measures at both the school and individual levels; (2) we examined similarities between the instru- mental and the expressive network by building multiplex networks and analyzing correlations between the degrees of the actors; and (3) we identified the principals as well as teachers with leadership roles and compared their degree centrality values descriptively. 7 � Results 7.1 � Differences in social network structures related to the collaboration on school improvement in two different accountability systems We first report on how school teams collaborated on school improvement in networks of two different accountability systems (California and Switzerland), focusing on the key elements of the network structure related to the quality of Educational Assessment, Evaluation and Accountability collaboration on school improvement. The network measures at the school level (Table 3) revealed that the networks of the Swiss schools were denser than the networks of the California schools. This indicated that there was more activity and therefore more opportunity to explore and discuss school improvement in the Swiss schools than in the California schools. Further, transitivity was higher in the Swiss schools than in the California schools, which meant that there were more closed triads; this indicated stronger relationships. Additionally, the results revealed that the California schools’ networks were less centralized than the Swiss schools’ networks (degree centralization), mean- ing that in the California schools, new school improvement ideas were discussed somewhat more evenly among actors than in Swiss schools. Central actors in Swiss schools’ networks tended to reach out to others (high outdegree centraliza- tion), whereas central actors in the California networks tended to be approached by others (higher indegree centralization). These results suggested that in Swiss networks, there were fewer actors who contributed more heavily to discussions on school improvement, such that they approached others to explore the further development of the school. In California networks, the actors who contributed more to discussions on school improvement had a stronger influence on school improvement, such that others approached them to discuss school improvement matters. There were no differences in the networks of the two accountability sys- tems regarding reciprocity and betweenness centralization and regarding indi- vidual network measures. Table 2   Description of network statistics Network statistic Description Density Proportion of actual relationships to possible relationships in the network. Indicator of how actively school teams exchange new ideas Reciprocity Tendency for relationships to be mutual; proportion of reciprocal ties to non-empty ties; indicator of mutual exchange between team members Transitivity Relationships between three actors in the network (triads); proportion of closed triads to open triads; indicator for subgroups or cliques in the network Centrality and centralization Importance of persons in the network. Centrality is about single actors. Centralization is a measure of the dispersion of centrality values across all actors. It summarizes the centrality of all persons in the network on a continuum between “all actors are equally central” and “one actor is maximally central.” Actors can be central regarding the following aspects: Degree Total number of relationships Indegree Number of incoming relationships; indicator for the prestige of a person Outdegree Number of outgoing relationships; indicator for the activity of a person Betweenness How often a person is on the shortest paths between pairs of other actors; indicator for access to information and control opportunities Educational Assessment, Evaluation and Accountability Ta bl e  3   N et w or k m ea su re s o n co lla bo ra tio n on sc ho ol im pr ov em en t i n C al ifo rn ia a nd S w itz er la nd (C H ) O n th e sc ho ol le ve l C en tra liz at io n C ou nt ry Sc ho ol N te ac he r M is si ng s D en - si ty Re ci pr oc ity Tr an si - tiv ity D eg re e In de gr ee O ut de gr ee B et w ee nn es s C H 1 29 4 0. 33 8 0. 48 7 0. 65 8 0. 42 3 0. 23 7 0. 68 5 0. 11 3 C H 2 34 4 0. 33 0 0. 41 3 0. 64 0 0. 43 0 0. 17 5 0. 69 0 0. 11 2 U SA 3 27 3 0. 27 1 0. 55 8 0. 57 3 0. 33 8 0. 42 2 0. 34 5 0. 20 4 U SA 4 34 5 0. 20 9 0. 47 0 0. 56 5 0. 28 5 0. 48 8 0. 24 6 0. 10 1 O n th e in di vi du al le ve l C en tra lit y D eg re e ra w In de gr ee ra w O ut de gr ee ra w B et w ee nn es s r aw C ou nt ry Sc ho ol M SD m in m ax M SD m in m ax M SD m in m ax M SD m in m ax C H 1 12 .2 7 7. 87 1 29 6. 13 3. 64 0 13 6. 13 6. 04 0 22 23 .4 3 35 .1 2 0 14 0 C H 2 14 .4 7 9. 82 3 46 7. 24 3. 22 2 13 7. 24 8. 2 0 33 21 .6 2 38 .2 2 0 19 8 U SA 3 14 .0 7 7. 04 4 31 7. 04 4. 51 1 18 7. 04 4. 16 0 16 22 .0 0 30 .5 1 0 14 9 U SA 4 13 .7 6 8. 27 0 32 6. 88 5. 80 0 23 6. 88 4. 61 0 15 29 .7 1 35 .4 9 0 13 3 Educational Assessment, Evaluation and Accountability 7.2 � Differences in two central conditions of collaboration on school improvement in two different accountability systems 7.2.1 � Trust relationships and their connection to collaboration on school improvement Focusing on trust relations in networks of two different accountability systems, the network measures at the school level (Table  4) revealed that the networks of the schools in Switzerland were again denser than the networks of the schools in Cali- fornia. This indicated that there were more trust relationships in the Swiss schools than in the California schools. This result was supported by the individual net- work measures: On average, actors in the Swiss networks had 16 (school 1) and 18 (school 2) trust relations, whereas in the California networks, actors had 10 (school 3) and 12 (school 4) trust relations. Also in these networks, transitivity was (slightly) higher in the Swiss schools than in the California schools, which suggested some- what stronger relationships in the Swiss schools. To examine the relationship between collaboration on school improvement and trust, we looked at the similarity of the collaboration and the trust network by bring- ing them together in a multiplex network. There were high and positive correlations between the school improvement and the trust networks at all four schools, mean- ing that in general, actors who were important in one network were important in the other network, too. The correlations for the Swiss schools were higher (school 1 = 0.738; school 2 = 0.676) than for the California schools (school 3 = 0.563; school 4 = 0.609). However, these correlations were not significantly different as assessed by Fisher’s z. 7.2.2 � Leader’s position and its connection to collaboration on school improvement and trust In the next step, we examined the role of leadership in the social network collabo- ration and in the social network trust in relation to the two different accountability systems by looking at the raw degree values of all actors for the school improvement network and the trust network in descending order (Table 5.). The principals and the teachers with leadership roles are highlighted in gray in the table. The data on the role of principals indicated that the principal played the most cen- tral role at only one school (school 2, CH) in both the school improvement network and the trust network. In schools 3 and 4 in California, the importance of the prin- cipal in the two networks deviated (considerably). At school 3, the principal held the most central position in the school improvement network but only a position in the middle field in the trust network; at school 4, this was the other way around. The picture was different again at school 1 in Switzerland, where the principal was not in the range that is one standard deviation above the mean in either network but was equally important in both networks. As a difference in the networks in the two accountability systems, it could be formulated that the principals in the California schools had different importance in terms of school improvement and trust, whereas Educational Assessment, Evaluation and Accountability Ta bl e  4   N et w or k m ea su re s o n tru st re la tio ns in C al ifo rn ia a nd S w itz er la nd (C H ) O n th e sc ho ol le ve l C en tra liz at io n C ou nt ry Sc ho ol N te ac he r M is si ng s D en si ty Re ci pr oc ity Tr an si tiv ity D eg re e In de gr ee O ut de - gr ee B et w ee nn es s C H 1 29 4 0. 28 3 0. 46 3 0. 62 7 0. 33 2 0. 26 9 0. 71 7 0. 07 4 C H 2 34 4 0. 28 4 0. 53 3 0. 55 6 0. 41 0 0. 23 1 0. 59 4 0. 12 8 U SA 3 27 3 0. 19 9 0. 62 9 0. 47 8 0. 39 2 0. 33 9 0. 57 0 0. 24 3 U SA 4 34 5 0. 17 7 0. 47 2 0. 52 6 0. 22 3 0. 12 6 0. 33 8 0. 06 4 O n th e in di vi du al le ve l C en tra lit y D eg re e ra w In de gr ee ra w O ut de gr ee ra w B et w ee nn es s r aw C ou nt ry Sc ho ol M SD m in m ax M SD m in m ax M SD m in m ax M SD m in m ax C H 1 16 .4 0 8. 50 3 35 8. 20 4. 26 2 16 8. 20 6. 68 0 29 20 .7 4 23 .8 1 0 78 C H 2 18 .7 6 9. 89 4 45 9. 38 3. 91 3 17 9. 38 7. 54 0 29 20 .7 6 33 .2 6 0 15 2 U SA 3 10 .3 7 5. 99 3 30 5. 19 2. 79 2 14 5. 19 4. 23 0 20 22 .9 6 38 .4 4 0 17 5 U SA 4 11 .7 1 6. 90 0 26 5. 85 2. 82 0 10 5. 85 5. 00 0 17 25 .1 2 26 .5 4 0 90 Educational Assessment, Evaluation and Accountability Ta bl e  5.    Li st of a ct or s’ d eg re e ce nt ra lit y on o rg an iz at io na l i m pr ov em en t r el at io ns , t ru st re la tio ns School1 im p. 29 28 26 24 22 21 20 A 19 17 B 13 12 11 10 10 10 10 9 9 9 9 9 8C 6 5 5 5 5 3 3 1 tru st 35 29 28 B 28 A 28 26 24 24 21 19 19 18 17 17 17 17 13 C 13 13 12 11 11 11 9 7 6 6 5 5 3 School2 im p. 46 32 29 E 29 C 29 25 B 22 D 19 A 18 16 16 16 15 G 15 14 F 14 13 12 12 11 11 10 9 8 8 7 7 6 5 4 4 4 3 3 tru st 45 44 A 33 31 B 29 28 26 D 25 23 C 22 F 22 22 21 20 19 18 17 17 17 16 E 16 13 G 13 13 13 13 11 11 9 9 7 7 4 4 School3 im p. 33 26 G 22 A 22 22 21 20 19 D 18 16 15 B 15 15 15 14 12 12 10 8E 8C 8 8 7 7 6 5F 4 tru st 30 D 21 A 20 14 13 G 13 13 13 12 11 11 11 11 11 11 9 9 8B 6C 6 6 5 5 4E 4F 4 3 School4 im p. 32 D 30 24 I 23 22 21 C 21 20 20 F 20 19 H 18 18 17 17 16 15 B 12 E 12 11 11 11 9 8G 8 7A 7 5 5 4 3 2 0 0 tru st 26 D 25 22 20 F 20 18 18 18 16 E 16 C 16 15 14 14 12 G 12 12 12 11 10 10 9B 8I 8 7A 7 5 4 4 3 3H 3 0 0 D ar k gr ay = sc ho ol p rin ci pa l; gr ay = te ac he r w ith le ad er sh ip ro le ; b la ck li ne = m ea n; d as he d lin e = st an da rd d ev ia tio n; su pe rs cr ip t l et te rs = sa m e pe rs on Educational Assessment, Evaluation and Accountability the principals in the Swiss schools seemed to be equally important in both networks, with the principal having once high and once medium importance. Looking at the teachers with leadership roles, we found that at three of the four schools (schools 2, 3, and 4), they had different importance in the two networks in most cases. Only at school 1 did the importance overlap in both networks. Thus, regarding these actors, there did not seem to be any differences in the networks in the two accountability systems. 8 � Discussion As educational systems around the globe vary widely in the accountability pres- sures they impose on schools, the question arises as to whether school improvement in school teams manifests differently in different accountability systems. School improvement is deeply rooted with collaboration among members of the school team within schools (García-Martínez et al., 2021; Nguyen & Ng, 2020). Therefore, collaboration in schools on school improvement has great potential for policy imple- mentation, teacher professional development, and ultimately student achievement (Daly, 2010; Moolenaar et al., 2012). In an exploratory case study, we analyzed the relationship between educational accountability systems and collaboration on school improvement in two strongly different accountability systems in a binational setting. We examined and compared social networks on school improvement, trust rela- tions, and leadership at two elementary schools in a California school district with a bureaucratic and legal accountability system and two schools in a Swiss canton with a professional accountability system. Focusing on our first research question, we descriptively compared the networks at schools in the different accountability systems. The results revealed that more dense networks with stronger relationships are found at the schools in Switzerland than at the schools in California. This suggests that school improvement activities and social cohesion are increased in a low-stakes system that evaluates the achieve- ment of standards by formative school inspections with no sanctions for detected discrepancies between actual and target. This professional accountability (Darling- Hammond, 2004) seems to open up more opportunities to talk about school improve- ment issues, and there is higher transitivity (Daly, 2010; Moolenaar, 2012). These results can be interpreted as indications that strengthen the theoretical assumptions. They show, albeit on a small scale, that a bureaucratic and legal accountability sys- tem tends to decrease collaboration, whereas a professional accountability system tends to increase collaboration in schools on school improvement. Our findings further underscore the direction of the findings by Coburn and Russell (2008). Their data in addition showed that interaction routines determine to whom school team members talk to and how often, and what they talk about. Connecting to the theory on routines and change of routines in schools (Maag Merki et al., 2023), we assume that schools in a professional accountability system are better able to build functional collaboration routines and change dysfunctional ones because they are expected to continuously professionalize (Darling-Hammond, Educational Assessment, Evaluation and Accountability 2004) and take responsibility for their schools’ development (Hatch, 2013). For this reason, it would be revealing for further research studies to look in more detail at collaboration routines in different accountability systems. In line with assumptions on the role of trust referring to our second research question, collaboration on school improvement goes hand-in-hand with trust (Brown et al., 2015; Tschannen-Moran, 2014). High levels of school improvement collaborations are associated with high levels of trust. The results of this study on prevailing trust in the networks of the different accountability systems reflect pre- vious findings that high-stakes monitoring systems tend to destroy trust, whereas professional accountability may improve trust (e.g., Daly, 2009; Ehren & Baxter, 2021). Distinctly more trust connections are evident in the networks in the profes- sional accountability system than in the bureaucratic and legal accountability sys- tem. These results are indications that strengthen the theoretical assumptions, as they support the idea that low accountability pressures may lead to more intense collaboration and the development and deepening of trust. Being under high-stakes bureaucratic accountability pressure might lead to a less strong focus on the impor- tant social ties between educators that may provide for the flow of new knowledge and practices. However, in contrast to our assumptions, the finding that the networks of the schools in California are less centralized than those of the schools in Switzerland is somewhat unexpected. Particularly related to theories of collective or distrib- uted leadership (Harris, 2003; Penuel et al., 2010), we assumed that the networks of schools in the professional accountability system would be more decentralized. One possible explanation is that a different type of centralization is evident in the two systems: Central individuals in the professional accountability system approach others more to talk about school improvement, whereas central individuals in the bureaucratic and legal accountability system are approached more by others in the team. This result might be related to Rogers’ (1962) theory on the diffusion of inno- vation. According to Rogers, innovations take their start from a few innovative indi- viduals, who introduce new ideas into a social system and try to convince others. It can thus be assumed that the central persons in the professional accountability system tend to be innovators approaching others to discuss school improvement mat- ters, whereas central persons in the bureaucratic and legal accountability system tend to be approached by persons to ensure that school improvement processes are approved by higher hierarchical levels. In our data, these central persons are not nec- essarily formal leaders. Further, there are no accountability-specific differences in the position of school principals and other persons with leadership functions. According to our theoretical assumptions, we expected leaders to be very central to monitoring and controlling school improvement in both accountability systems. In this respect, the role of per- sons with leadership functions in different accountability systems needs to be inves- tigated in more depth. Also, it is particularly important to analyze school leaders’ perspectives on the accountability system implemented in their educational system. It might be that although the accountability system is formally low-stakes compared to other systems, the school leaders might experience pressure (Jäger et al., 2012). Educational Assessment, Evaluation and Accountability Accordingly, collaborative practice in schools may be influenced not only by the objective but also by the perceived characteristics of accountability systems. This study has several limitations, the most significant of which is the sam- ple size. The data from four schools are not enough to allow reliable statements about differences in collaboration on school improvement between accountabil- ity systems and to draw causal inferences. This is particularly pertinent when considering the countries’ cultural contexts within which the schools are situ- ated, and it is imperative to acknowledge that the results cannot be attributed purely to differences in accountability systems. Furthermore, variation between schools also within the different accountability systems could be expected. As mentioned above, we do not seek to produce generalizable findings for a wider population but rather to contribute to an evolving theory concerning the relation- ship between educational accountability and collaboration on school improve- ment. We therefore consider our study to be a very important first step toward a deeper understanding of collaboration on school improvement in different accountability systems in international settings. No studies to date have taken an international perspective on the link between educational accountability and collaboration on school improvement. But this kind of relationship is critical to any form of school reform or school change (Coburn & Russell, 2008). As countries are borrowing accountability policies from one another and countries tend to have policies on one pole or the other, it is very important to understand the effects that different accountability systems have on schools and their actors. Our results show that our assumptions on the link between accountability pres- sure and collaboration on school improvement are worth pursuing further. This can be achieved by including not only a larger sample and more data on school processes on the organizational, interpersonal, and personal level (Mitchel & Sackney, 2011) but also by including additional types or blended types of accountability (Darling-Hammond, 2004). We see another limitation in the fact that we could not link the social network data to further data, e.g., questionnaire data or qualitative interviews. We are con- vinced that the learning and working together of school team members to improve schools can be best studied and mapped with social networks, as reforms and changes in schools implicate social interactions (Daly, 2010). However, to obtain a more in-depth look at the quality and content of collaboration, it would be use- ful to complement social network analysis with other data. For these reasons, we encourage researchers to conduct further studies with methods complementary to social network analysis to examine collaboration on school improvement in different accountability systems. Taken together, this study contributes to our understanding of how collaboration in school teams on school improvement plays out in internationally diverse account- ability systems. This exploratory case study provides first insights into the relation- ship between accountability systems and collaboration on school improvement in school teams. The paper thus contributes to theory building on commonalities that might cross international boundaries. Educational Assessment, Evaluation and Accountability Author contribution  Andrea Wullschleger: conceptualization, methodology, formal analysis, investiga- tion, data curation, writing—original draft, visualization. Alan J. Daly: conceptualization, methodology, investigation, writing—original draft. Nicolette van Halem: investigation, data curation, writing—review and editing. Katharina Maag Merki: investigation, writing—original draft. Beat Rechsteiner: investiga- tion, data curation, writing—review and editing. Funding  Open access funding provided by FHNW University of Applied Sciences and Arts Northwest- ern Switzerland. Data availability  The data that support the findings of this study are available on reasonable request from the corresponding author. The data are not publicly available due to their containing information that could compromise the privacy of research participants. Declarations  Conflict of interest  The authors declare no competing interests. Open Access  This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Com- mons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. References Altrichter, H., & Kemethofer, D. (2015). Does accountability pressure through school inspections pro- mote school improvement? School Effectiveness and School Improvement, 26(1), 32–56. https://​doi.​ org/​10.​1080/​09243​453.​2014.​927369 Amels, J., Krüger, M. L., Suhre, C. J. M., & van Veen, K. (2020). The effects of distributed leadership and inquiry-based work on primary teachers’ capacity to change: Testing a model. School Effective- ness and School Improvement, 31(3), 468–485. https://​doi.​org/​10.​1080/​09243​453.​2020.​17463​63 Bourdieu, P. (1986). The forms of capital. In J. Richardson (Ed.), Handbook of theory and research for the sociology of education (pp. 241–258). Greenwood. Brandes, U., Kosub, S., spsampsps Nick, B. (2012). Was messen Zentralitätsindizes? [What do centrality indexes measure?]. In M. Hennig spsampsps C. Stegbauer (Eds.), Die Integration von Theorie und Methode in der Netzwerkforschung (pp. 33–52). VS Verlag für Sozialwissenschaften. https://​doi.​org/​ 10.​1007/​978-3-​531-​93464-8_3 Brown, C., Daly, A., & Liou Y.-H. (2015). Improving trust, improving schools: Findings from a social network analysis of 43 primary schools in England. Journal of Professional Capital and Commu- nity, 1(1), 69–91. https://​doi.​org/​10.​1108/​JPCC-​09-​2015-​0004 Bryant, D. A., Wong, Y. L., & Adames, A. (2020). How middle leaders support in-service teachers’ on- site professional learning. International Journal of Educational Research., 100, 101530. https://​doi.​ org/​10.​1016/j.​ijer.​2019.​101530 Bryk, A. S., & Schneider, B. (2002). Trust in schools: A core resource for improvement. Russell Sage Foundation. CAASPP (California Assessment of Student Performance and Progress System). (2021). California’s statewide student assessment system. https://​www.​caaspp-​elpac.​org. Accessed 3 Jul 2025. California School Dashboard. (2017). Explore information about your local school and district. https://​ www.​casch​oolda​shboa​rd.​org/. Accessed 3 Jul 2025. Camburn, E. M., Kimball, S. M., & Lowenhaupt, R. (2008). Going to scale with teacher leadership: Lessons learned from a districtwide literacy coach initiative. In M. M. Mangin & S. R. Stoelinga (Eds.), Effec- tive teacher leadership: Using research to inform and reform (pp. 120–143). Teachers College Press. http://creativecommons.org/licenses/by/4.0/ https://doi.org/10.1080/09243453.2014.927369 https://doi.org/10.1080/09243453.2014.927369 https://doi.org/10.1080/09243453.2020.1746363 https://doi.org/10.1007/978-3-531-93464-8_3 https://doi.org/10.1007/978-3-531-93464-8_3 https://doi.org/10.1108/JPCC-09-2015-0004 https://doi.org/10.1016/j.ijer.2019.101530 https://doi.org/10.1016/j.ijer.2019.101530 https://www.caaspp-elpac.org https://www.caschooldashboard.org/ https://www.caschooldashboard.org/ Educational Assessment, Evaluation and Accountability Campbell, S., Greenwood, M., Prior, S., Shearer, T., Walkem, K., Young, S., Bywaters, D., & Walker, K. (2020). Purposive sampling: Complex or simple? Research case examples. Journal of Research in Nursing, 25(8), 652–661. https://​doi.​org/​10.​1177/​17449​87120​927206 CCSSI (Common Core State Standards Initiative). (2022). Preparing America’s students for success. https://​www.​cores​tanda​rds.​org/. Accessed 3 Jul 2025.  Cerna, L. (2014). Trust: What it is and why it matters for governance and education. OECD Education Working Papers No. 108. OECD Publishing. https://​doi.​org/​10.​1787/​19939​019 Coburn, C. E., & Russell, J. L. (2008). District policy and teachers’ social networks. Educational Evalua- tion and Policy Analysis, 30(3), 203–235. https://​doi.​org/​10.​3102/​01623​73708​321829 Coburn, C. E., Hill, H. C., & Spillane, J. P. (2016). Alignment and accountability in policy design and implementation: The common core state standards and implementation research. Educational Researcher, 45(4), 243–251. https://​doi.​org/​10.​3102/​00131​89X16​651080 Coleman, J. S. (1990). Foundations of social theory. Belknap Press of Harvard University Press. Coppe, T., Thomas, L., Pantić, N., Froehlich, D. E., Sarazin, M., & Raemdonck, I. (2022). The use of social capital in teacher research: A necessary clarification. Frontiers in Psychology, 13:866571. https://​www.​front​iersin.​org/​artic​les/​10.​3389/​fpsyg.​2022.​866571 Daly, A. J. (2009). Rigid response in an age of accountability: The potential of leadership and trust. Edu- cational Administration Quarterly, 45(2), 168–216. https://​doi.​org/​10.​1177/​00131​61X08​330499 Daly, A. J. (2010). Mapping the terrain: Social network theory and educational change. In A. J. Daly (Ed.), Social network theory and educational change (pp. 1–16). Harvard University Press. Daly, A., Der-Martirosian, C., Ong-Dean, C., Park, V & Wishard-Guerra, A. (2011). Leading under sanc- tion: Principals’ perceptions of threat rigidity, efficacy, and leadership in underperforming schools. Leadership and Policy in Schools, 10(2), 171–206. https://​doi.​org/​10.​1080/​15700​763.​2011.​557517 Daly, A. J., Finnigan, K. S., Jordan, S., Moolenaar, N. M., & Che, J. (2014). Misalignment and perverse incentives: Examining the politics of district leaders as brokers in the use of research evidence. Edu- cational Policy, 28(2), 145–174. https://​doi.​org/​10.​1177/​08959​04813​513149 Darling-Hammond, L. (2004). Standards, accountability, and school reform. Teachers College Record, 106(6), 1047–1085. Datnow, A., Lockton, M., & Weddle, H. (2020). Redefining or reinforcing accountability? An examina- tion of meeting routines in schools. Journal of Educational Change, 21, 109–134. https://​doi.​org/​10.​ 1007/​s10833-​019-​09349-z Datnow, A., Weddle, H., & Lockton, M. (2022). Teachers’ use of evidence to inform practice: Examining cohesion, regulation, and accountability in California. In C. Brown & J. R. Malin (Eds.), The Emer- ald handbook of evidence-informed practice in education: Learning from international contexts (pp. 35–46). Emerald Publishing. De Lima, J. A. (2010). Studies of networks in education: Methods for collecting and managing high-qual- ity data. In A. J. Daly (Ed.), Social network theory and educational change (pp. 243–258). Harvard University Press. Diamond, J. B. (2012). Accountability policy, school organization, and classroom practice: Partial recou- pling and educational opportunity. Education and Urban Society, 44(2), 151–182. https://​doi.​org/​10.​ 1177/​00131​24511​431569 EDK (Schweizerische Konferenz der kantonalen Erziehungsdirektoren). (2011). Die interkantonale Verein- barung über die Harmonisierung der obligatorischen Schule (HARMOS-Konkordat) vom 14. Juli 2007 [Intercantonal agreement on harmonization of compulsory education (HARMOS) of 14 July 2007]. EDK (Schweizerische Konferenz der kantonalen Erziehungsdirektoren). (2022). Nationale Bildungsziele [National educational goals]. https://​www.​edk.​ch/​de/​themen/​harmos/​natio​nale-​bildu​ngszi​ele Ehren, M., & Baxter, J. (2021). Trust, accountability and capacity: Three building blocks of education system reform. In M. Ehren & J. Baxter (Eds.), Trust, accountability and capacity in education sys- tem reform: Global perspectives in comparative education (pp. 1–29). Routledge. Ehren, M. C. M., Gustafsson, J. E., Altrichter, H., Skedsmo, G., Kemethofer, D., & Huber, S. G. (2015). Comparing effects and side effects of different school inspection systems across Europe. Compara- tive Education, 51(3), 375–400. https://​doi.​org/​10.​1080/​03050​068.​2015.​10457​69 Emmerich, M., & Maag Merki, K. (2014). Die Entwicklung von Schule: Theorie—Forschung—Praxis [The improvement of schools: Theory—research—practice]. Julius Beltz GmbH & Co. KG. https://​ doi.​org/​10.​3262/​EEO20​140338 Finnigan, K. S., & Daly, A. (2010). Learning at a system level: Ties between principals of low-perform- ing schools and central office leaders. In A. J. Daly (Ed.), Social network theory and educational change (pp. 179–195). Harvard University Press. https://doi.org/10.1177/1744987120927206 https://www.corestandards.org/ https://doi.org/10.1787/19939019 https://doi.org/10.3102/0162373708321829 https://doi.org/10.3102/0013189X16651080 https://www.frontiersin.org/articles/10.3389/fpsyg.2022.866571 https://doi.org/10.1177/0013161X08330499 https://doi.org/10.1080/15700763.2011.557517 https://doi.org/10.1177/0895904813513149 https://doi.org/10.1007/s10833-019-09349-z https://doi.org/10.1007/s10833-019-09349-z https://doi.org/10.1177/0013124511431569 https://doi.org/10.1177/0013124511431569 https://www.edk.ch/de/themen/harmos/nationale-bildungsziele https://doi.org/10.1080/03050068.2015.1045769 https://doi.org/10.3262/EEO20140338 https://doi.org/10.3262/EEO20140338 Educational Assessment, Evaluation and Accountability Freeman, L. C. (1978). Centrality in social networks conceptual clarification. Social Networks, 1(3), 215– 239. https://​doi.​org/​10.​1016/​0378-​8733(78)​90021-7 Fuhse, J. A. (2016). Soziale Netzwerke: Konzepte und Forschungsmethoden [Social networks: Concepts and research methods] (2nd ed.). UVK Verlagsgesellschaft. https://​doi.​org/​10.​36198/​97838​38549​811 García-Martínez, I., Montenegro-Rueda, M., Molina-Fernández, E., & Fernández-Batanero, J. M. (2021). Mapping teacher collaboration for school success. School Effectiveness and School Improvement, 32(4), 631–649. https://​doi.​org/​10.​1080/​09243​453.​2021.​19257​00 Graham, P. (2007). Improving teacher effectiveness through structured collaboration: A case study of a professional learning community. RMLE Online, 31(1), 1–17. https://​doi.​org/​10.​1080/​19404​476.​ 2007.​11462​044 Granovetter, M. S. (1973). The strength of weak ties. American Journal of Sociology, 78, 1360–1380. Hallam, P. R., Smith, H. R., Hite, J. M., Hite, S. J., & Wilcox, B. R. (2015). Trust and collaboration in PLC Teams: Teacher relationships, principal support, and collaborative benefits. NASSP Bulletin, 99(3), 193–216. https://​doi.​org/​10.​1177/​01926​36515​602330 Hallinger, P., & Liu, S. (2016). Leadership and teacher learning in urban and rural schools in China: Meeting the dual challenges of equity and effectiveness. International Journal of Educational Development, 51, 163–173. https://​doi.​org/​10.​1016/j.​ijedu​dev.​2016.​10.​001 Hamilton, L. S., Stecher, B. M., Russell, J. L., Marsh, J. A., & Miles, J. (2008). Accountability and teach- ing practices: School-level actions and teacher responses. In B. Fuller, M. K. Henne, & E. Hannum (Eds.), Strong stakes, weak schools: The benefits and dilemmas of centralized accountability (pp. 31–66). Emerald. Harris, A. (2003). Teacher leadership as distributed leadership: Heresy, fantasy or possibility? School Leadership and Management, 23(3), 313–324. Hatch, T. (2013). Beneath the surface of accountability: Answerability, responsibility and capacity-build- ing in recent education reforms in Norway. Journal of Educational Change, 14, 113–138. https://​ doi.​org/​10.​1007/​s10833-​012-​9206-1 Hendriks, M., & Steen, R. (2012). Results from school leadership effectiveness studies (2005–2010). In J. Scheerens (Ed.), School leadership effects revisited: Review and meta-analysis of empirical studies (pp. 65–129). Springer. Hofer, S. I., Holzberger, D., & Reiss, K. (2020). Evaluating school inspection effectiveness: A system- atic research synthesis on 30 years of international research. Studies in Educational Evaluation, 65, 100864. https://​doi.​org/​10.​1016/j.​stued​uc.​2020.​100864 Hopkins, D. (2005). Introduction: Tensions in and prospects for school improvement. In D. Hopkins (Ed.), The practice and theory of school improvement: International handbook of educational change (pp. 1–21). Springer. Hoy, W. K., & Tschannen-Moran, M. (2003). The conceptualization and measurement of faculty trust in schools: The omnibus T-Scale. In W. K. Hoy & C. G. Miskel (Eds.), Studies in leading and organ- izing schools (pp. 181–208). Information Age. Hubers, M. D., Moolenaar, N. M., Schildkamp, K., Daly, A. J., Handelzalts, A., & Pieters, J. M. (2017). Share and succeed: The development of knowledge sharing and brokerage in data teams’ network structures. Research Papers in Education, 33(2), 216–38. https://​doi.​org/​10.​1080/​02671​522.​2017.​ 12866​82 Jäger, D. J., Maag Merki, K., Oerke, B., & Holmeier, M. (2012). Statewide low-stakes tests and a teach- ing to the test effect? An analysis of teacher survey data from two German states. Assessment in Education: Principles, Policy & Practice, 19(4), 451–467. https://​doi.​org/​10.​1080/​09695​94X.​2012.​ 677803 Kelchtermans, G. (2006). Teacher collaboration and collegiality as workplace conditions: A review. Zeitschrift Für Pädagogik, 52(2), 220–237. Klieme, E. (2004). Begründung, Implementation und Wirkung von Bildungsstandards [Justification, implementation and impact of educational standards]. Zeitschrift Für Pädagogik, 50, 625–634. https://​doi.​org/​10.​25656/​01:​4831 Loeb, S., Edley, C., Imazeki, J., & Stipek, D. (2018). Getting down to facts II: Current conditions and paths forward for California schools. Policy Analysis for California Education. https://​getti​ngdow​ ntofa​cts.​com/​sites/​defau​lt/​files/​2018-​09/​GDTFII%​20Sum​mary%​20Rep​ort.​pdf. Accessed 3 Jul 2025. Louis, K. S., Leithwood, K., Wahlstrom, K. L., & Anderson, S. E. (2010). Learning from leadership: Investigating the links to improved student learning. New York: The Wallace Foundation. https://​ www.​walla​cefou​ndati​on.​org/​knowl​edge-​center/​school-​leade​rship/​key-​resea​rch/​Docum​ents/​Inves​ tigat​ing-​the-​Links-​to-​Impro​ved-​Stude​nt-​Learn​ing.​pdf https://doi.org/10.1016/0378-8733(78)90021-7 https://doi.org/10.36198/9783838549811 https://doi.org/10.1080/09243453.2021.1925700 https://doi.org/10.1080/19404476.2007.11462044 https://doi.org/10.1080/19404476.2007.11462044 https://doi.org/10.1177/0192636515602330 https://doi.org/10.1016/j.ijedudev.2016.10.001 https://doi.org/10.1007/s10833-012-9206-1 https://doi.org/10.1007/s10833-012-9206-1 https://doi.org/10.1016/j.stueduc.2020.100864 https://doi.org/10.1080/02671522.2017.1286682 https://doi.org/10.1080/02671522.2017.1286682 https://doi.org/10.1080/0969594X.2012.677803 https://doi.org/10.1080/0969594X.2012.677803 https://doi.org/10.25656/01:4831 https://gettingdowntofacts.com/sites/default/files/2018-09/GDTFII%20Summary%20Report.pdf https://gettingdowntofacts.com/sites/default/files/2018-09/GDTFII%20Summary%20Report.pdf https://www.wallacefoundation.org/knowledge-center/school-leadership/key-research/Documents/Investigating-the-Links-to-Improved-Student-Learning.pdf https://www.wallacefoundation.org/knowledge-center/school-leadership/key-research/Documents/Investigating-the-Links-to-Improved-Student-Learning.pdf https://www.wallacefoundation.org/knowledge-center/school-leadership/key-research/Documents/Investigating-the-Links-to-Improved-Student-Learning.pdf Educational Assessment, Evaluation and Accountability Maag Merki, K. (2016). Theoretische und empirische Analysen der Effektivität von Bildungsstandards, standardbezogenen Lernstandserhebungen und zentralen Abschlussprüfungen [Theoretical and empirical analyses of the effectiveness of educational standards, standard-based tests, and cen- tral final examinations]. In H. Altrichter & K. Maag Merki (Eds.), Handbuch Neue Steuerung im Schulsystem [Handbook New Steering in the School System], (2nd ed., pp. 151–182). VS Verlag für Sozialwissenschaft. Maag Merki, K. (2021). Schulentwicklungsforschung [School improvement research]. In T. Hascher, T.-S. Idel, & W. Helsper (Eds.), Handbuch Schulforschung [Handbook of school research] (pp. 1–21). Springer Fachmedien. https://​doi.​org/​10.​1007/​978-3-​658-​24734-8_​71-1 Maag Merki, K., Wullschleger, A., & Rechsteiner, B. (2023). Adapting routines in schools when facing challenging situations: Extending previous theories on routines by considering theories on self-reg- ulated and collectively regulated learning. Journal of Educational Change. https://​doi.​org/​10.​1007/​ s10833-​022-​09459-1 Mitchell, C., & Sackney, L. (2011). Profound improvement: Building learning-community capacity on living-system principles (2nd ed.). Routledge. Moolenaar, N. (2012). A social network perspective on teacher collaboration in schools: Theory, meth- odology, and applications. American Journal of Education, 119(1), 7–39. https://​doi.​org/​10.​1086/​ 667715 Moolenaar, N., & Sleegers, P. J. C. (2010). Social networks, trust, and innovation: The role of relation- ships in supporting an innovative climate in Dutch schools. In A. J. Daly (Ed.), Social network the- ory and educational change (pp. 97–114). Harvard University Press. Moolenaar, N., Daly, A. J., & Sleegers, P. J. C. (2012). Exploring patterns of interpersonal relationships among teachers. A social network theory perspective. In T. Wubbels, J. van Tartwijk, P. Brok, & J. Levy (Eds.), Interpersonal relationships in education (pp. 87–101). Sense Publishers. Moolenaar N., Karsten S., Sleegers P., & Daly A. (2014). Linking social networks and trust at multiple levels: Examining Dutch elementary schools. In D. Van Maele, P. Forsyth, & M. Van Houtte (Eds.), Trust and school life: The influence of trust on learning, teaching, leading, and bridging (pp. 207– 228). Springer. https://​doi.​org/​10.​1007/​978-​94-​017-​8014-8_​10 Muckenthaler, M., Tillmann, T., Weiß, S., & Kiel, E. (2020). Teacher collaboration as a core objective of school development. School Effectiveness and School Improvement, 31(3), 486–504. https://​doi.​org/​ 10.​1080/​09243​453.​2020.​17475​01 Nguyen, D., & Ng, D. (2020). Teacher collaboration for change: Sharing, improving, and spread- ing. Professional Development in Education, 46(4), 638–651. https://​doi.​org/​10.​1080/​19415​257.​ 2020.​17872​06 Nguyen, D., Harris, A., & Ng, D. (2019). A review of the empirical research on teacher leadership (2003–2017). Journal of Educational Administration, 58(1), 60–80. O’Day, J. A. (2002). Complexity, accountability, and school improvement. In S. H. Fuhrman & R. F. Elmore (Eds.), Redesigning accountability systems for education. Teachers College Press. OECD. (2013). Synergies for better learning: An international perspective on evaluation and assess- ment. In OECD reviews of evaluation and assessment in education. https://​www.​oecd-​ilibr​ary.​ org/​educa​tion/​oecd-​revie​ws-​of-​evalu​ation-​and-​asses​sment-​in-​educa​tion_​22230​955 Penninckx, M. (2017). Effects and side effects of school inspections: A general framework. Studies in Educational Evaluation, 52, 1–11. https://​doi.​org/​10.​1016/j.​stued​uc.​2016.​06.​006 Penninckx, M., & Vanhoof, J. (2015). Insights gained by schools and emotional consequences of school inspections. A review of evidence. School Leadership & Management, 35(5), 477–501. https://​doi.​org/​10.​1080/​13632​434.​2015.​11070​36 Penuel, W. R., Kenneth, A. F., & Krause, A. (2010). Between leaders and teachers: Using social net- work analysis to examine the effects of distributed leadership. In A. J. Daly (Ed.), Social network theory and educational change (pp. 159–178). Harvard University Press. Robins, G. (2015). Doing social network research: Network-based research design for social scien- tists. Sage. Robinson, V., Lloyd, C., & Rowe, K. (2008). The impact of leadership on student outcomes: An anal- ysis of the differential effects of leadership types. Educational Administration Quarterly, 44(5), 564–588. Rogers, E. M. (1962). Diffusion of innovations. Free Press. Ronfeldt, M., Farmer, S. O., McQueen, K., & Grissom, J. A. (2015). Teacher collaboration in instruc- tional teams and student achievement. American Educational Research Journal, 52(3), 475–514. https://​doi.​org/​10.​3102/​00028​31215​585562 https://doi.org/10.1007/978-3-658-24734-8_71-1 https://doi.org/10.1007/s10833-022-09459-1 https://doi.org/10.1007/s10833-022-09459-1 https://doi.org/10.1086/667715 https://doi.org/10.1086/667715 https://doi.org/10.1007/978-94-017-8014-8_10 https://doi.org/10.1080/09243453.2020.1747501 https://doi.org/10.1080/09243453.2020.1747501 https://doi.org/10.1080/19415257.2020.1787206 https://doi.org/10.1080/19415257.2020.1787206 https://www.oecd-ilibrary.org/education/oecd-reviews-of-evaluation-and-assessment-in-education_22230955 https://www.oecd-ilibrary.org/education/oecd-reviews-of-evaluation-and-assessment-in-education_22230955 https://doi.org/10.1016/j.stueduc.2016.06.006 https://doi.org/10.1080/13632434.2015.1107036 https://doi.org/10.3102/0002831215585562 Educational Assessment, Evaluation and Accountability SARC (School Accountability Report Card). (2022). California public & nonpublic, nonsectarian schools annually provide information to the community to allow public comparison of schools for student achievement, environment, resources & demographics. https://​sarco​nline.​org/​public/​ findA​Sarc. Accessed 3 Jul 2025. SCCRE (Swiss Coordination Centre for Research in Education). (2023). Education report Switzerland 2023. Swiss Coordination Centre for Research in Education. Spillane, J. P., & Louis, K. S. (2002). School improvement processes and practices: Professional learning for building instructional capacity. Yearbook of the National Society for the Study of Education, 101(1), 83–104. https://​doi.​org/​10.​1111/j.​1744-​7984.​2002.​tb000​05.x Spillane, J. P., Diamond, J. B., Burch, P., Hallett, T., Jita, L., & Zoltners, J. (2002). Managing in the middle: School leaders and the enactment of accountability policy. Educational Policy, 16(5), 731–762. Spillane, J. P., & Anderson, L. (2019). Negotiating policy meanings in school administrative practice: Practice, professionalism, and high-stakes accountability in a shifting policy environment. In D. Hung, S.-S. Lee, Y. Toh, A. Jamaludin, & L. Wu (Eds.), Innovations in educational change: Cultivating ecologies for schools (pp. 121–145). Springer Nature. https://​doi.​org/​10.​1007/​ 978-​981-​13-​6330-6_7 Tschannen-Moran, M. (2001). Collaboration and the need for trust. Journal of Educational Administra- tion, 39(4), 308–331. https://​doi.​org/​10.​1108/​EUM00​00000​005493 Tschannen-Moran, M. (2014). The interconnectivity of trust in schools. In D. Van Maele, P. B. Forsyth, spsampsps M. Van Houtte (Eds.), Trust and school life: The influence of trust on learning, teaching, leading, and bridging (pp. 57–81). Springer. https://​doi.​org/​10.​1007/​978-​94-​017-​8014-8_3 ÜGK Schweiz (Überprüfung der Grundkompetenzen). (2022). Informationen für Eltern, Schülerinnen und Schüler, Lehrpersonen, Schulleitende und Forschende [Information for parents, students, teach- ers, school leaders, and researchers]. https://​www.​uegk-​schwe​iz.​ch/. Accessed 3 Jul 2025. UNESCO. (2017). Global education monitoring report: Accountability in education. UNESCO. Vangrieken, K., Dochy, F., Raes, E., & Kyndt, E. (2015). Teacher collaboration: A systematic review. Educational Research Review, 15, 17–40. Wahlstrom, K. L., & Louis, K. (2008). How teachers experience principal leadership: The roles of profes- sional community, trust, efficacy, and shared responsibility. Educational Administration Quarterly, 44(4), 458–495. https://​doi.​org/​10.​1177/​00131​61X08​321502 Wasserman, S., & Faust, K. (1994). Social network analysis: Methods and applications. Cambridge Uni- versity Press. Weddle, H., Lockton, M., & Datnow, A. (2020). Teacher collaboration in school improvement. Oxford Bibliographies. Publisher’s Note  Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Authors and Affiliations Andrea Wullschleger1   · Alan J. Daly2   · Nicolette van Halem3   · Katharina Maag Merki4   · Beat Rechsteiner4  * Andrea Wullschleger andrea.wullschleger@fhnw.ch 1 School of Education, University of Applied Sciences and Arts Northwestern Switzerland, Windisch, Switzerland 2 Department of Education Studies, University of California, San Diego, CA, USA 3 Department of Child Development and Education, University of Amsterdam, Amsterdam, Netherlands 4 Institute of Education, University of Zurich, Zurich, Switzerland https://sarconline.org/public/findASarc https://sarconline.org/public/findASarc https://doi.org/10.1111/j.1744-7984.2002.tb00005.x https://doi.org/10.1007/978-981-13-6330-6_7 https://doi.org/10.1007/978-981-13-6330-6_7 https://doi.org/10.1108/EUM0000000005493 https://doi.org/10.1007/978-94-017-8014-8_3 https://www.uegk-schweiz.ch/ https://doi.org/10.1177/0013161X08321502 http://orcid.org/0000-0003-4390-3835 http://orcid.org/0000-0002-6760-8374 http://orcid.org/0000-0001-8155-7254 http://orcid.org/0000-0002-0215-1684 http://orcid.org/0000-0003-2555-431X Collaboration on school improvement under different educational accountability systems in two countries Abstract 1 Accountability systems and their role in school improvement 1.1 Standardized tests and school improvement 1.2 School inspections and school improvement 2 Two accountability systems in contrast 2.1 Accountability system in the USA and more specifically in California 2.2 Accountability system in Switzerland and more specifically in the canton of interest 3 School improvement as a social and collaborative process in school teams 3.1 Trust as a prime resource for collaboration on school improvement 3.2 (Collective) leadership as a prime resource for collaboration on school improvement 3.3 Social network structures as key elements of quality collaboration on school improvement 4 State of research: the relationship between different accountability systems and collaboration on school improvement 5 Aim, research questions, and assumptions on collaboration on school improvement under different educational accountability systems 6 Method 6.1 Participants and procedure 6.2 Measures 6.3 Analytic approach 7 Results 7.1 Differences in social network structures related to the collaboration on school improvement in two different accountability systems 7.2 Differences in two central conditions of collaboration on school improvement in two different accountability systems 7.2.1 Trust relationships and their connection to collaboration on school improvement 7.2.2 Leader’s position and its connection to collaboration on school improvement and trust 8 Discussion References