Methodology for heuristic evaluation of the accessibility of statistical charts for people with low vision and color vision deficiency

Abstract Purpose: Statistical charts have an important role in conveying, clarifying and simplifying information, and have a significant presence in fields such as education, scientific research or journalism. Despite numerous advances in the field of digital accessibility, charts are still a challenge for people with low vision and color vision deficiency (CVD) and create barriers that hinder their accessibility. The research presented in this paper aim is to create a heuristic set of indicators to evaluate the accessibility of statistical charts focusing on the needs of people with low vision and CVD. Methods: The set of heuristics presented has been developed based on the methodology by Quiñones et al. (2018), which consists of 8 stages: (1) a state of the art literature review; (2 and 3) analysis and description of the most relevant information obtained from this research; (4, 5, and 6) selection and specification of a first set of heuristics relating them to existing heuristics; (7) validation; and (8) refining the set to obtain a final list of heuristics. Results: A first set of heuristics (17 indicators) has been developed and applied on two heuristic evaluations, and has been amplified to 18 indicators. The final set covers the needs of the user profiles with low vision as well as the needs of the CVD and poor contrast sensitivity users. Conclusion: this research is a first step to widen accessibility requirements to statistical charts and to take into consideration users with low vision and CVD, often forgotten in accessibility research.