Typically developing preschooler's location of digital photos on speech generating devices using visual scene displays

Abstract

Purpose: This study examined preschoolers’ (19-25 months) accuracy in selecting graphic symbols on the main page of a dynamic visual scene display (VSD) using embedded and non- embedded symbols. Method: Twenty participants were equally divided into two experimental conditions that included embedded or non-embedded VSDs. Participants were assigned to one of the two experimental conditions and were subsequently taught to select a superordinate symbol on the main page of a symbol display that linked to a second page of each of nine symbols. The participant then selected the target symbol corresponding to the referent displayed at the beginning of the instructional opportunity. After an initial session of nine opportunities participants were provided with up to seven additional intervention sessions. Maintenance was examined subsequent to mastery. Results: Children in both embedded and non-embedded treatment groups demonstrated improvement over the course of the study. There were no statistically significant differences between children’s performance in the embedded and non-embedded VSD conditions. Post hoc analyses revealed that chronological age, receptive language level as measured by the Receptive One Word Picture Vocabulary Test (Brownell, 2000), and gender were significant predictors of participant accuracy. Descriptive analyses revealed some patterns suggesting that participants in the embedded condition made modestly greater gains than participants in the non-embedded condition. Conclusions: The differential effect of embedded and non-embedded symbol displays was not demonstrated with participants between 19-25 months of age. Based on the current evidence, if VSDs are to be used in an intervention it is likely best for educators to select embedded or non-embedded VSDs based on a comparison of individual learner needs and abilities and to use individual performance data to guide the intervention decision. Limitations of the current investigation are discussed.