A research study was conducted to investigate a control and display system for use with communication aids by physically disabled persons. A modification of a row/column scanning system was investigated to increase speed and accuracy of access to the communication system by six children with athetoid cerebral palsy. Four systems were compared: row/column directed scan (two switches); row/column auto scan (one switch); row auto scan (one switch); and column auto scan (one switch). Results revealed no significant differences among systems for scan time to select the correct target. The row/column auto scan (the most widely prescribed system for severely disabled persons) resulted in significantly more errors than any of the other three systems. It was also found that individuals who would have been or had already been prescribed a single switch system were able to operate two switches. (Author/CL)