Learning of embedded and non-embedded visual scene display AAC technologies by typically developing 2-year-olds.

Abstract

Purpose: Evidence suggests that young children learn to locate symbols on visual scene displays (VSDs) more efficiently than on traditional grid displays (Drager, Light, Speltz & Jefferies, 2003). This study examined the effects of two different types of VSDs on three typically-developing two-year-olds’ abilities to locate 36 symbols that represented vocabulary items. The VSD types were embedded VSDs that clearly displayed all associated symbols on the main page and non-embedded VSDs that set the context but did not directly display the associated symbols on the main page. Method: Three children participated in 10 experimental sessions during which they located 36 symbols that represented vocabulary items using a DynaVox Vmax™. The DynaVox Vmax™ had six VSDs on the main page; three VSDs were embedded and three VSDs were non-embedded. Dependent measures included the accuracy of selection and the latency of correct selections. One maintenance session was conducted 6 ½ weeks after the final experimental session. Results: Results support those of previous studies which demonstrated that learning to navigate speech generating devices (SGDs) is difficult for young learners. All participants performed faster and more accurately with embedded VSDs than with non-embedded VSDs. Two of the three participants were more accurate locating the correct scene for the symbols in the first 12 opportunities compared to their performance during the last 12 opportunities of the session. Conclusion: Overall accuracy was low for both embedded and non-embedded conditions. Children in the current investigation failed to approximate a criterion of performance in either condition that would allow reliable communication. However, there was a significant difference favoring embedded scene displays when compared to non-embedded scene displays. Implications for future research as well as for clinical/educational applications are discussed.