Participants engage in two conditions: (1) Parent-implemented Broad Target Speech Recast (BTSR), (2) Parent-implemented BTSR combined with clinician-implemented speech therapy

This is a nonconcurrent multiple probe single-case experimental design with staggered introduction of conditions across participants. All participants receive both interventions, but the interventions are introduced in separate phases and evaluated independently and in combination.

This is not a crossover or parallel group design. Rather than having separate arms or randomization, each participant serves as their own control over time, allowing for individualized evaluation of intervention effects.

Broad Target Speech Recasts (BTSR) is a speech intervention technique in which an adult immediately recasts a child's incorrect articulation by providing a corrected version of the word in a naturalistic, meaningful context. Unlike traditional articulation therapy, which focuses on isolated sound drills, BTSR integrates correction seamlessly into conversation without requiring the child to repeat or imitate the model.

This approach is rooted in principles of implicit learning, where repeated exposure to accurate speech models facilitates phonological development over time. BTSR differs from traditional minimal pair or phonetic placement techniques in that it does not involve explicit instruction or direct prompts for self-correction. Instead, it provides high-frequency, naturalistic exposure to correct phoneme production within functional language use.

The percent of accurate phoneme productions per target, which is derived by dividing the number of correct productions by the total possible points for each target and then multiplying by 100. Accurate phoneme production is defined by a speech-language pathologist's judgment of perceptual accuracy through the lens of broad transcription.

The Goldman-Fristoe Test of Articulation, Third Edition (GFTA-3) is a standardized assessment used to evaluate speech sound production in children, adolescents, and young adults (ages 2;0-21;11). It measures articulation skills by assessing a child's ability to produce consonant sounds in different word positions (initial, medial, final) and in connected speech. The test provides standard scores, percentile ranks, and age-equivalent scores.

Scores are standardized with a mean of 100 and a standard deviation of 15. Standard scores range from 40 to 160, with higher scores indicating better articulation abilities.