A rule-based multimodal computer-access system for upper-limb accessibility: Design and preliminary usability evaluation of the Turkish voice-command module

Computer access can be difficult for people who cannot use conventional mouse-and-keyboard input effectively. This study documents the design of a rule-based multimodal computer-access prototype comprising a Turkish voice-command module and a face/head-motion cursor-control module, and reports a preliminary usability evaluation limited to the voice-command component. Before development, formative consultations were conducted with two individuals with upper-limb impairments, one individual with a visual impairment, and six non-disabled stakeholders. After development, 25 non-disabled proxy participants completed a predefined scenario of 19 common computer tasks using the Turkish voice-command module. Task completion, completion time, facilitator assistance, and descriptive post-scenario feedback were recorded. All participants reached the predefined outcome for every task within an assisted protocol. Facilitator assistance was required in 28 task-participant instances across six tasks, most frequently when copying selected text, selecting a search-result link, and creating a new file. Mean task-completion times ranged from 9 to 240 seconds. The observations point to command operations and workflow transitions that may warrant further refinement, including clearer feedback, more visible error recovery, simplified multi-step interactions, and greater personalisation. However, the evaluation did not include participants with upper-limb impairments, did not test the face/head-motion module, and did not use standardised usability, workload, or cognitive-load measures. The results therefore offer preliminary proxy-user observations about the Turkish voice-command module rather than validation of the complete multimodal system or its accessibility for the intended user population.