“…CTD has been shown to be both effective and efficient in teaching students of various ages and with various disabilities. For example, it has been used successfully to teach word definitions to 10-year-old students with severe learning disorders (Schuster, Stevens, & Doak, 1990), sight words to students ages 10 to 11 years with moderate mental retardation (Schuster, Griffen, & Wolery, 1992), sight words to 4-to 5-year-old preschoolers with moderate delays (Alig-Cybriwsky, , and response to the lures of strangers to preschool children ages 3 to 5 years with developmental delays (Gast, Collins, Wolery, & Jones, 1993).…”