ABSTRACT
Assistive technologies have become increasingly widespread, yet many developers have been criticized for a lack of usability evaluation. This paper presents a research study where usability evaluation was done on a haptic science learning system using the critical incident technique . The system was evaluated by seven teachers experienced in working with students with visual disabilities. The Retrospective Think Aloud (RTA) method was conducted as teachers used the system. Two researchers analyzed and elicited critical incidents from video recordings of teachers ' interaction with the system. Results from the verbal protocol analysis revealed several areas of concern regarding system usability.
