Use of the Alternating Treatment Design to Evaluate Intervention in Low Vision Rehabilitation

This article illustrates the use of the alternating treatment design to assess the effectiveness of individualized interventions in low vision rehabilitation. The design was used to determine if enlarging copy with a photocopier and adding contrast would be effective in reducing the amount of time a visually impaired student required to read a map and graph. Two levels of magnification were compared to determine the level of intervention to be provided.