Assessing text and web accessibility for people with autism spectrum disorder

Abstract

People with Autism Spectrum Disorder experience di culties with reading comprehension and information processing, which a ect their school performance, employability and social inclusion. The main goal of this work is to investigate new ways to evaluate and improve text and web accessibility for adults with autism. The rst stage of this research involved using eye-tracking technology and comprehension testing to collect data from a group of participants with autism and a control group of participants without autism. This series of studies resulted in the development of the ASD corpus, which is the rst multimodal corpus of text and gaze data obtained from participants with and without autism. We modelled text complexity and sentence complexity using sets of features matched to the reading di culties people with autism experience. For document-level classi cation we trained a readability classi er on a generic corpus with known readability levels (easy, medium and di cult) and then used the ASD corpus to evaluate with unseen user-assessed data. For sentencelevel classi cation, we used for the rst time gaze data and comprehension testing to de ne a gold standard of easy and di cult sentences, which we then used as training and evaluation sets for sentence-level classi cation. The ii results showed that both classi ers outperformed other measures of complexity and were more accurate predictors of the comprehension of people with autism. We conducted a series of experiments evaluating easy-to-read documents for people with cognitive disabilities. Easy-to-read documents are written in an accessible way, following speci c writing guidelines and containing both text and images. We focused mainly on the image component of these documents, a topic which has been signi cantly under-studied compared to the text component; we were also motivated by the fact that people with autism are very strong visual thinkers and that therefore image insertion could be a way to use their strengths in visual thinking to compensate for their di culties in reading. We investigated the e ects images in text have on attention, comprehension, memorisation and user preferences in people with autism (all of these phenomena were investigated both objectively and subjectively). The results of these experiments were synthesised in a set of guidelines for improving text accessibility for people with autism. Finally, we evaluated the accessibility of web pages with di erent levels of visual complexity. We provide evidence of existing barriers to nding relevant information on web pages that people with autism face and we explore their subjective experiences with searching the web through survey questions.