South Laura, Borkin Michelle A
IEEE Trans Vis Comput Graph. 2023 Jan;29(1):374-384. doi: 10.1109/TVCG.2022.3209359. Epub 2022 Dec 16.
Accessibility guidelines place restrictions on the use of animations and interactivity on webpages to lessen the likelihood of webpages inadvertently producing sequences with flashes, patterns, or color changes that may trigger seizures for individuals with photosensitive epilepsy. Online data visualizations often incorporate elements of animation and interactivity to create a narrative, engage users, or encourage exploration. These design guidelines have been empirically validated by perceptual studies in visualization literature, but the impact of animation and interaction in visualizations on users with photosensitivity, who may experience seizures in response to certain visual stimuli, has not been considered. We systematically gathered and tested 1,132 interactive and animated visualizations for seizure-inducing risk using established methods and found that currently available methods for determining photosensitive risk are not reliable when evaluating interactive visualizations, as risk scores varied significantly based on the individual interacting with the visualization. To address this issue, we introduce a theoretical model defining the degree of control visualization designers have over three determinants of photosensitive risk in potentially seizure-inducing sequences: the size, frequency, and color of flashing content. Using an analysis of 375 visualizations hosted on bl.ocks.org, we created a theoretical model of photosensitive risk in visualizations by arranging the photosensitive risk determinants according to the degree of control visualization authors have over whether content exceeds photosensitive accessibility thresholds. We then use this model to propose a new method of testing for photosensitive risk that focuses on elements of visualizations that are subject to greater authorial control - and are therefore more robust to variations in the individual user - producing more reliable risk assessments than existing methods when applied to interactive visualizations. A full copy of this paper and all study materials are available at https://osf.io/8kzmg/.
无障碍指南对网页上动画和交互性的使用进行了限制，以降低网页无意中生成带有闪烁、图案或颜色变化的序列的可能性，因为这些可能会引发光敏性癫痫患者的癫痫发作。在线数据可视化通常包含动画和交互性元素，以构建叙事、吸引用户或鼓励探索。这些设计指南已在可视化文献中的感知研究中得到实证验证，但可视化中的动画和交互对光敏用户的影响尚未得到考虑，这些用户可能会因某些视觉刺激而癫痫发作。我们使用既定方法系统地收集并测试了1132个交互式和动画可视化的癫痫诱发风险，发现当前用于确定光敏风险的方法在评估交互式可视化时不可靠，因为风险评分会因与可视化交互的个体不同而有显著差异。为了解决这个问题，我们引入了一个理论模型，该模型定义了可视化设计师对潜在癫痫诱发序列中光敏风险的三个决定因素的控制程度：闪烁内容的大小、频率和颜色。通过对托管在bl.ocks.org上的375个可视化进行分析，我们根据可视化作者对内容是否超过光敏无障碍阈值的控制程度来排列光敏风险决定因素，从而创建了一个可视化中光敏风险的理论模型。然后，我们使用这个模型提出一种新的光敏风险测试方法，该方法侧重于可视化中受作者控制程度更高的元素，因此对个体用户的变化更具鲁棒性，在应用于交互式可视化时，比现有方法能产生更可靠的风险评估。本文的完整副本和所有研究材料可在https://osf.io/8kzmg/获取。
