Retrospective Protocol

A usability evaluation method in which participants complete tasks first and then describe their thought processes, decisions, and experiences immediately afterwards, rather than verbalising concurrently during the task. Retrospective protocols are particularly important in accessibility research because concurrent think-aloud methods can be impractical for users with certain disabilities — for example, blind screen reader users face auditory channel conflicts when asked to speak while listening to screen reader output, and deaf users cannot sign while performing manual tasks. While retrospective data may capture decision-making processes less precisely than concurrent protocols, it avoids the cognitive overload and task disruption associated with concurrent verbalisation.