Usability Testing - An Aphasia Perspective
Abi Roper, Ian Davey, Stephanie Wilson, Timothy Neate, Jane Marshall, Brian Grellmann · 2018 · Proceedings of the 20th International ACM SIGACCESS Conference on Computers and Accessibility (ASSETS 2018) · doi:10.1145/3234695.3241481
Summary
This experience report from City, University of London presents how classic usability testing methods were adapted to include people with aphasia, co-authored with Ian Davey, a person with aphasia who participated in the adapted testing. Aphasia is a language impairment acquired following brain damage (most commonly stroke), affecting an estimated 0.1-0.4% of the developed world's population. It can impair speaking, understanding, reading, and writing to varying degrees while leaving intelligence intact — as Ian describes, "My intelligence is unaffected: I could understand what was being said and done around me but I was just unable to respond." Classic usability testing techniques like think-alouds and written task scenarios require a minimum degree of linguistic competence, effectively excluding people with aphasia. The paper describes how Abi Roper, a trained speech and language therapist, facilitated two usability testing sessions where Ian tested Facebook (which he already used) and Tumblr (which he had never used) on an iPad. The adapted methodology evolved from over 8 years of working with people with aphasia on technology design and evaluation.
Key findings
Six key adaptations were made to classic usability testing: (1) short, direct tasks replaced open-ended scenarios, introduced verbally one-at-a-time by the facilitator; (2) communicative gesture and physical artefacts like picture cards were used to facilitate communication and shared understanding; (3) think-alouds were replaced with intermittent reflections and probes from the facilitator during natural pauses — for example, after observing Ian visually searching a page, asking "so what were you looking for just now?" which allowed Ian to report almost synchronously without diverting cognitive resources to challenging linguistic composition; (4) additional time was factored in for pacing and alternative communication; (5) post-test questions were presented in both written and verbal formats with visual rating scales; (6) a speech and language therapist acted as facilitator. The testing successfully identified both accessible tasks (opening apps, exploring feeds, liking/commenting) and challenging ones (changing profile pictures, writing bios, searching for information). Ian found drop-down menus, buttons, and tags challenging, and unfamiliar icons in Tumblr created barriers. From Ian's perspective, the tasks were "about right" in length, the atmosphere made him feel at ease to express views freely, and he endorsed the approach of keeping instructions as simple as possible — "even if that means the task may appear childish to others." The paper itself was co-authored using adapted methods: Ian's contributions were structured as emailed question-and-answer responses, composed one at a time, with a filmed face-to-face session for review.
Relevance
This paper makes a compelling case that usability testing must be adapted to include people with aphasia — not as an optional nicety but as a requirement for developing accessible technology. The specific adaptations described are immediately actionable for any UX team. The involvement of a speech and language therapist as facilitator is particularly noteworthy — the paper argues that clinical expertise in communication support is essential for this work, and researchers without this background should seek collaboration with speech therapists. For accessibility practitioners, the broader lesson is that standard user research methods carry hidden linguistic assumptions that exclude significant populations. The co-authorship model — where Ian is a named author contributing through adapted writing methods — exemplifies inclusive research practice. Ian's first-person perspective provides insights that a researcher observing from outside could not capture, such as the fatigue caused by aphasia worsening throughout the day and his preference for building complexity gradually rather than receiving all instructions upfront.
Tags: aphasia · usability testing · cognitive accessibility · stroke · communication accessibility · participatory design · speech and language therapy · inclusive research