The document reviewed 22 studies that used constant time delay (CTD) or progressive time delay (PTD) procedures to teach skills to students with autism spectrum disorder (ASD). It found that both procedures were effective in teaching a variety of discrete and chained skills. PTD was more efficient, with lower error rates and faster transfer of stimulus control. Further research is needed on specific diagnostic criteria and generalization programming.

1. Time Delay Procedures for Teaching Students with Autism Spectrum Disorders Gabriela Walker, Ed. S. Department of Communication Sciences & Special Education - University of Georgia Department of Educational policy Studies – University of Illinois at Urbana-Champaign

19. Results – Demographic: AGE Preschool: 3-5 yrs.; Elementary: 6-11; Adolescence: 12-18; Adulthood: 21>

22. Results – Demographic: Settings

37. Results – Outcomes: Efficiency

39. Results – Outcomes: Treatment Comparisons 11.6 3.7 SLP 10.75 9.1 CTD Error percentage Mean sessions Ault et al., 1988 13 141 SLP 4.5 120 (- 6 hrs.) PTD Error percentage No. of sessions Godby et al., 1987

40. Results – Outcomes: Treatment Comparisons 609 - LTM 47 - PTD No. of errors Mean sessions Heckaman et al., 1998 - 56.7 Visual Fading - 47.3 PTD Error percentage No. of sessions Matson et al., 1993

42. Dipipi, C. M., Jitendra, A. K., & Miller, J. A. (2001). Reducing repetitive speech: Effects of strategy instruction. Preventing School Failure , 45 , 177-181. 1.Baseline; 2.Time delay; 3.Self-recording+DRO; 4.Maintenance 1 2 3 4

43. Wall, M. E. & Gast, D. L. (1997). Caregivers’ use of constant time delay to teach leisure skills to adolescents or young adults with moderate or severe intellectual disabilities. Education and Training in Mental Retardation and Developmental Disabilities , 340-356