Supporting Symbolic Communication through Naturalistic Visually Adapted AAC Intervention

Abstract

Aim:  

Despite the central role of visual access in aided AAC, these considerations have rarely been addressed in intervention research. Most AAC studies either require functional vision or fail to report participants’ visual status (Nattress et al., 2025), despite high prevalence of visual impairment (VI) among aided communicators (Holbrook et al., 2017). When individuals with VI are included, studies often demonstrate methodological limitations, including limited rigor, focus on a single pragmatic function, reliance on adult-directed approaches, and lack of communication partner instruction (Brittlebank et al., 2024). Few studies have applied naturalistic approaches for individuals with multiple disabilities including VI while involving communication partners such as educators and parents (Pope et al., 2024).

To improve outcomes for early communicators with VI, this study incorporated methodology from the ImPAACT program (Kent-Walsh et al., 2013) and cascading coaching model research (Gallegos et al., 2024). This exploratory sequential mixed methods study: (a) developed an initial version of ImPAACT-VI to support symbolic turn-taking; (b) incorporated educator perspectives; and (c) conducted an early efficacy study examining educator and student outcomes.

Research questions included:

(1) What are facilitators and barriers to implementing ImPAACT-VI in schools?

(1a) What adaptations do educators recommend?

(1b) How do educators rate contextual fit, usability, and feasibility via the PRISM Contextual Survey Instrument (PCSI)?

(1c) What additional adaptations are recommended?

(2) What is the effect on educators’ implementation and generalization of partner strategies?

(3) What is the effect on students’ symbolic turn-taking and use of relevant symbols?

Methods: Two semi-structured focus groups (educational assistants, teachers) informed intervention refinement using the revised PRISM framework (Glasgow et al., 2024). Rapid qualitative methods included consensus coding and member checking (Kowalski et al., 2024). A multiple-probe across participants single-case design evaluated the effectiveness of the ImPAACT-VI Program. Student inclusion criteria were: 3;0-6;0 years; diagnoses of visual impairment (VI) or multiple disabilities including VI; intentional communication (Communication Matrix Level III); expressive vocabulary of 1-25 words; English and/or Spanish home language. The 12-session ImPAACT-VI program taught educators an 8-step cognitive strategy for implementing naturalistic communication techniques through modeling, guided practice, feedback, and fading supports. Outcomes included educator accurate strategy use, student independent symbolic turns, and number of different symbols (NDSym). Visual analysis, Tau-U effect sizes, and descriptive statistics were calculated. Procedural fidelity was 91-100%; reliability exceeded the 80% standard.

Results: Focus groups identified key themes regarding program content, logistics, and foundational supports, emphasizing researcher flexibility and individualized intervention. Educator strategy use increased from 0-14% at baseline to ≥90% post-instruction with generalization to novel activities (range = 88-100%) and maintenance at 3 months (range = 83-100%). Student symbolic turns increased from 0-1 turns at baseline to 6-17 turns per session with generalization (range = 6-16 turns), and maintenance (range = 5-16 turns). NDSym increased from 0-1 symbol at baseline to 3-9 symbols with generalization (range = 2-9) and maintenance (range = 4-9). Visual analysis demonstrated substantial level changes and positive trends. Tau-U was 1.0 for all educator and student outcomes, indicating very large effects. PCSI findings reflected positive perceptions of program acceptability and suitability for similar students.

Conclusion: 

ImPAACT-VI had positive effects on educators’ use of naturalistic strategies, students’ turn-taking frequency, and students’ number of different symbols. Clinical implications related to the positive use of the 8-step cognitive strategy approach for communication partner instruction and program modifications which included coaching rather than role plays, activity planners, and visually adapted AAC.