Acquisition of tacting using a speech-generating device in group learning environments for preschoolers with autism
Lorah, Elizabeth R., & Parnell, Ashley (2017). Journal of Developmental and Physical Disabilities, 29, 597-609.
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examining3Students, gradePK
Practice Guide
Review Details
Reviewed: March 2026
- Practice Guide (findings for Acquistion of tacting using speech-generating device and time delay - Lorah & Parnell (2017))
- Single Case Design
- Meets WWC standards with reservations because it is a SCD design where the independent variable is manipulated by the researcher, each outcome is measured systematically over time by multiple assessors with a sufficient number of assessment points and inter-assessor agreement, but there are an insufficient number of phases and/or assessments per phase to meet without reservations.
This review may not reflect the full body of research evidence for this intervention.
Evidence Tier rating based solely on this study. This intervention may achieve a higher tier when combined with the full body of evidence.
Findings
To view more detailed information about the study findings from this review, please download findings data here.
Evidence Tier rating based solely on this study. This intervention may achieve a higher tier when combined with the full body of evidence.
Sample Characteristics
Characteristics of study sample as reported by study author.
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Female: 67%
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Arkansas
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Race Other or unknown 100% -
Ethnicity Other or unknown 100% -
Eligible for Free and Reduced Price Lunch Other or unknown 100%
Study Details
Setting
Participants attended a 4-week preschool group that emulated a preschool learning environment and was affiliated with a university. The class included four children in total. The intervention was held in the classroom during circle time, which lasted an average of 5 minutes, and occurred 2–3 times per day and at the same time each day (i.e., arrival, 90 minutes after arrival, and then immediately prior to departure).
Study sample
The three participants were 3 or 4 years old and diagnosed with autism spectrum disorder. One student was a male and two students were females. The study did not report other demographic information.
Intervention Group
During each session, participants were prompted to tact (or identify) two animal icons using their speech-generating device (SGD). The teacher would read the book "Where's Spot" and stop on a page to prompt a child to lift a flap on the page in the book, revealing an animal. If the child lifted the flap, the teacher then waited five seconds for the child to tact the animal on their SGD. If the child did not lift the flap, the teacher lifted the flap and pointed to the animal and waited five seconds for the child to tact. If the child did not tact within the timeframe or selected a picture-icon that did not correspond to the target animal, the trial was scored as a "no" and the interventionist provided a full, physical prompt to evoke correct responding. Session counts ranged from nine to 18 sessions over a 4-week period. The teacher provided exaggerated social praise for independent tacting and milder social praise for prompted responses.
Comparison Group
There is no comparison group in single-case designs. The baseline condition was similar to the intervention condition, except the teacher did not provide any prompting (i.e., lifting the flap and pointing to the target animal) if the student did not independently tact within 5 seconds.
Support for implementation
Study participants had previously acquired the ability to discriminate between more than 10 picture symbols on the screen of the iPad® SGD, as measured by the Verbal Behavior-Milestones Assessment and Placement Program Barriers Assessment (VB-MAPP). Both the teacher and interventionists were trained on the study procedures prior to the onset of the study.
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For more, please see the WWC Glossary entry for improvement index.
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The mean score of students in the comparison group.
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Study findings for this report.
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