title: Text entry via character stroke disambiguation for an adolescent with severe motor impairment and cortical visual impairment.
abstract: This study proposed a single-switch text entry system by hierarchical scanning of character strokes for an 11-year-old girl with severe physical disabilities and low vision. She could only perceive magnified straight line segments and chords presented against high-contrast, colored backgrounds. In a descriptive case study, the participant used the proposed system in the community for 8 months. Assessment included theoretical evaluation of text entry performance and empirical evaluation of the participant's proficiency. The proposed system had a lower error-free text entry rate but comparable proneness to user error as a real-world implementation of row-column virtual scanning keyboard with character frequency layout. The participant's proficiency, in terms of mean number of single-switch activations and time to type one character, showed statistically significant improvements as the case study progressed. The proposed system feasibly addressed the participant's typing needs, in a context where traditional row-column scanning and codeword-based text entry systems were not successful.
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Brian
authors.initials: B
authors.lastname: Leung
authors.forename: Madeleine
authors.initials: M
authors.lastname: Yates
authors.forename: Pierre
authors.initials: P
authors.lastname: Duez
authors.forename: Tom
authors.initials: T
authors.lastname: Chau
mesh_terms: D002547:Cerebral Palsy / Q000503:physiopathology / Q000534:rehabilitation*; D002648:Child; D003143:Communication Devices for People with Disabilities; D019988:Children with Disabilities / Q000534:rehabilitation*; D005260:Female; D006801:Humans; D014584:User-Computer Interface; D015354:Vision, Low