Table 2.

Overview of variables by construct, procedure, period, role, and research question (RQ).

Construct	Procedure	Variable	Period	Role (RH)
Speech comprehensibility	Two 20-min conversational speech samples	Slope of the growth curve for the proportion of utterance attempts in which every word attempt was glossed, averaged across two 20-min speech samples	1–4	Outcome (1, 2)
Verbal imitation	Dynamic assessment of verbal imitation	Weighted sum of exactly imitated verbal stimuli	1, 4	Putative moderator (1)
Cumulative exposure to speech recasts	1. 25% of therapy sessions coded for use of speech recasts.	Product of number of speech recasts per minute, average duration of therapy session, and total therapy sessions attended	Monthly during treatment phase	Putative mediator (2, 3)
	2. Record of duration of therapy sessions.
	3. Record of student attendance to therapy sessions