Table 1.

Descriptions of existing verbal behavior repertoires for James, Justin, and Roger, as demonstrated on ABLLS-R assessments conducted outside of and prior to the study

	Age	Echoic	Motor imitation	Listener	Tact	Intraverbal
James	7 years	Up to 6 words	Novel movements	Objects, pictures, emotions, items by feature, function, and class	Objects, pictures, emotions, items by feature, function, and class, letters and sight words	Fill in phrases and functions, answer “what” and “where” questions, answer questions about personal information
Justin	4 years	Up to 6 words	Novel movements	Objects, pictures, items by feature, function, and class	Tact parts of items and up to 3-word carrier phrases, letters and sight words	Songs and phrases, fill-ins regarding the features, functions, and classes
Roger	8 years	Up to 6 words	Novel movements	Objects, pictures, emotions, items by feature, function, and class	Objects, pictures, emotions, items by feature, function, and class, letters and sight words	Answers to who, what, where, and why questions regarding personal information, objects and common activities