This paper reflects on how Web cognition is experienced by blind users employing screen-readers for Web interaction. Many of the differences in Web interaction between sighted users and users of screen-readers arise from the serial way in which Web pages are rendered by screen-readers. We begin by examining the ways in which these differences are brought about through the functionality of current screen-readers. The mismatch between the spatial layout of Web pages and the temporal nature of speech imply a substantially increased cognitive load for Web interactions. The paper reports findings from a survey and a task-based study which provides some practical examples of the way these issues appear in real contexts of use. In particular, the wide differences between the initial impressions and mental models of Web pages gained by sighted and visually impaired users, and the influence that these and other interaction characteristics have on collaborative tasks. We propose a draft taxonomy of errors for cross-modal Web interaction, and examine how non-speech sound might be employed to address the different categories of error in the draft taxonomy.
|Publication status||Published - 2008|