Access to Augmentative and Alternative Communication: Arranging the Interface

PURPOSE: The purpose of this study was to identify whether fewer, complex pages or more, simpler pages provided more efficient communication for the user of an augmentative and alternative communication (AAC) device. This study examined the effectiveness of single-page displays versus multipage displays in the design of AAC systems for the efficiency of communication. Currently, there is little research on methods to improve the rate of communication, especially through communication board layout. This study has provided insight into the processes of visual complexity and motor control in message construction. The study aimed to answer two research questions: Does spreading larger communication symbols over four pages result in faster message construction, compared with using all symbols on a single page of the same size? Does spreading larger communication symbols over four pages result in more accurate message construction, compared with placing all symbols on a single page of the same size?

DESIGN: A quasi-experimental research design was used to compare communication rate and accuracy of a single-page display and a multipage display. Twenty-six participants were used throughout this study to test efficiency with different keyboard interfaces. The participants were a mix of men and women ages 18–56 yr. Participants were recruited by word of mouth at a small, suburban college campus.

METHOD: Each participant completed three trials using a single-page display with 60 symbols per page and three trials using a four-page display with 12 symbols per page. Random assignment was used to denote the keyboard used for the first set of trials. Each message was evaluated for the number of words typed in the 20-min trial. This number, divided by 20, gave the words per min. Each message was evaluated for accuracy using Microsoft Word’s Compare Documents feature; messages were compared to the master randomizer document. The speed and accuracy of message generation were compared using a matched-pairs student’s t statistic.

RESULTS: In the initial stages of learning, a single, more complex paged keyboard produced faster message construction than was achieved by a set of simpler pages in a keyboard. However, the accuracy of the message was substantially better using the multipage layout. This result indicates that in settings where accuracy is more important than speed, a multipage layout would be preferred. In settings where speed is more important than accuracy, a single-page layout would be preferred.

DISCUSSION: This study sought to provide first steps toward addressing the difference in functionality of single-page layouts versus multipage layouts. This is relevant to the occupational therapy scope of practice because occupational therapists should be part of an interdisciplinary team when assessing communication needs of an individual to produce the best AAC device fit. The role of the occupational therapist is to balance the demands of the AAC device and the functional capacity of the individual to enable communication in multiple environments.

CONCLUSION: The results provide some guidance, but not the final answer. The results of this study may provide guidance to aid in the selection of AAC displays and designing selection methods for AAC users. The study encompassed the impact of cognitive and perceptual processing and motor control for functioning with a single-page and multipage layout. The overall goal was to provide the opportunity to AAC users to close the gap between verbal communication and output communication of AAC devices.

References

American Speech–Language–Hearing Association. (2015). Information for AAC users. Retrieved from http://www.asha.org/public/speech/disorders/InfoAACUsers/

Dynavox. (2014). Dynamic AAC goals. Retrieved from http://www.dynavoxtech.com/training/toolkit/details.aspx?id=32

Fitts, P. M. (1954). The information capacity of the human motor system in controlling the amplitude of movement. Journal of Experimental Psychology, 47, 381–391. https://doi.org/10.1037/h0055392

Johnston, S. S., & Feeley, K. M. (2012). AAC system features. In S. S. Johnston, K. M. Feeley, & E. A. Jones (Eds.), Augmentative and alternative communication for individuals with moderate to severe disabilities (pp. 51–79). Baltimore: Paul H. Brookes.

Schneck, C. M., & Amundson, S. J. (2010). Prewriting and handwriting skills. In J. Case-Smith & J. C. O’Brien (Eds.), Occupational therapy for children (6th ed., pp. 555–582). St. Louis, MO: Mosby Elsevier.