Severity of Usability and Accessibility Problems in eCommerce and eGovernment Websites

Abstract

Guidelines are available to address website usability and accessibility and these often rate the importance of different problems encountered by users. However, users still experience problems when interacting with sites and little research has been conducted to assess which problems are the most severe. Prioritizing problems during website development is needed to ensure efficient and effective use of limited resources. To investigate the issue of the severity of usability and accessibility problems, a study was conducted comparing the severity ratings of problems found in a group of sites by two sets of guidelines (WCAG1.0 for accessibility and the Health and Human Services (HHS) guidelines for usability), by an expert and by users. The research revealed that the majority of the most severe problems are identified in existing guidelines. However, not all of the less severe problems are identified. A significant agreement between expert and users on the relative severity of problems was found, but the expert rated problems more severely than the users. Surprisingly, no relationship was found between the ratings in either the WCAG1.0 or HHS guidelines and the ratings given by the users and the expert. Therefore, we conclude that developers should obtain severity ratings from users or an expert rather than relying on those provided by guidelines.