Re-designing scanning to reduce learning demands: The performance of typically developing 2-year-olds

John McCarthy, Janice Light, Kathryn Drager, David McNaughton, Laura Grodzicki, Jonathan Jones, Elizabeth Panek, Elizabeth Parkin

Research output: Contribution to journalArticlepeer-review

50 Scopus citations


Children with severe motor impairments who cannot use direct selection are typically introduced to scanning as a means of accessing assistive technology. Unfortunately, it is difficult for young children to learn to scan because the design of current scanning techniques does not always make explicit the offer of items from the selection array; furthermore, it does not provide explicit feedback after activation of the switch to select the target item. In the current study, scanning was redesigned to reduce learning demands by making both the offer of items and the feedback upon selection more explicit through the use of animation realized through HTML and speech output with appropriate intonation. Twenty typically developing 2-year-olds without disabilities were randomly assigned to use either traditional scanning or enhanced scanning to select target items from an array of three items. The 2-year-olds did not learn to use traditional scanning across three sessions. Their performance in Session 3 did not differ from that in Session 1; they did not exceed chance levels of accuracy in either session (mean accuracy of 20% for Sessions 1 and 3). In contrast, the children in the enhanced scanning condition demonstrated improvements in accuracy across the three 10-20-min sessions (mean accuracies of 22 and 48% for Sessions 1 and 3, respectively). There were no reliable differences between the children's performances with the two scanning techniques for Session 1; however, by Session 3, the children were more than twice as accurate using the enhanced scanning technique compared to the traditional design. Results suggest that by redesigning scanning, we may be able to reduce some of the learning demands and thereby reduce some of the instructional time required for children to attain mastery. Clinical implications, limitations, and directions for future research and development are discussed.

Original languageEnglish (US)
Pages (from-to)269-283
Number of pages15
JournalAAC: Augmentative and Alternative Communication
Issue number4
StatePublished - Dec 2006

All Science Journal Classification (ASJC) codes

  • Rehabilitation
  • Speech and Hearing


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