Comparison of progressive and constant time-delay procedures in teaching community-sign word reading

The effectiveness and efficiency of a progressive and constant time-delay procedure was compared. Three students with moderate mental retardation were taught to read 12 words commonly found on community signs. Six words were taught using a progressive time-delay procedure and six, using a constant time-delay procedure. The effectiveness of the two procedures was evaluated through the use of a parallel treatments design across sign words and replicated across subjects. Results show that both procedures were effective, with the constant time-delay procedure slightly more efficient in terms of number of minutes of direct instructional time and number of sessions to criterion. Both procedures generated error percentages of 1.4 or less. Findings were discussed in terms of selecting instructional strategies.