Square-glyphs. Assessing the readability of multidimensional spatial data visualized as square-glyphs

Type
01A - Journal article
Editors
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Parent work
International Journal of Cartography
Special issue
DOI of the original publication
Link
Series
Series number
Volume
9
Issue / Number
3
Pages / Duration
449-465
Patent number
Publisher / Publishing institution
Taylor & Francis
Place of publication / Event location
Edition
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Abstract
Glyphs have long been used to approach the challenge of visualising multidimensional data with geospatial reference. Depending on the glyph design, data-dense visualizations of several concurrent data dimensions can be created. The square-glyph is a compound glyph to represent up to four data dimensions, e.g. walkability indices, with reference to a gridded geographic space (Bleisch and Hollenstein 2018 [Exploring multivariate representations of indices along linear geographic features. Proceedings of the 2017 International Cartographic Conference, Washington D.C. (pp. 1–5)]). In this paper, we present a user study to evaluate the readability and interpretability of the square-glyphs. We compare user performance with square-glyph plots containing two and four simultaneously mapped data dimensions under different value compositions. Our results show that the user performance with square-glyphs does not decrease as the number of data dimensions represented increases from two to four. The study results indicate no significant differences in efficiency and effectiveness between the four-dimensional square-glyphs and the two-dimensional square-glyphs. The average values of five adjacent glyphs can be estimated with a mean error of eight percentage points. The results suggest that equal value distances between the displayed dimensions are more accurately perceived in a lower-value composition than in higher-value arrangements.
Keywords
Glyph visualization, Square-glyphs, Multidimensionalspatial data, Evaluation, Userstudy
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ISBN
ISSN
2372-9333
2372-9341
Language
English
Created during FHNW affiliation
Yes
Strategic action fields FHNW
Publication status
Published
Review
Peer review of the complete publication
Open access category
Hybrid
License
'https://creativecommons.org/licenses/by/4.0/'
Citation
Müller, G., Hollenstein, D., Cöltekin, A., & Bleisch, S. (2023). Square-glyphs. Assessing the readability of multidimensional spatial data visualized as square-glyphs. International Journal of Cartography, 9(3), 449–465. https://doi.org/10.1080/23729333.2023.2235492