Using Constant Time Delay to Teach Sight Words to Students Identified as Deafblind

The present study investigated the use of constant time delay (CTD) to teach sight word recognition to students with impairments in both vision and hearing. A multiple probe design across word lists, replicated across an elementary-aged student and middle school-aged student, was used to evaluate the efficacy of CTD in teaching sight words. Both participants demonstrated mastery across three word lists. A functional relation between CTD and improved word recognition was demonstrated. The researchers informally investigated the effect of instructive feedback on correct spelling of the targeted sight words for the elementary-aged student; however, improved spelling did not occur. The results of the present study contribute to the limited body of intervention research targeting individuals identified as deafblind (i.e., co-occurring impairments in both vision and hearing).