The efficacy of technology use by people with intellectual disability: A single-subject design meta-analysis.

Authors: West, M. & Anderson, J.
Year Published 2008
Publication Journal of Special Education Technology
Volume 23
Number 3
Pages 21-30
Publisher The Council for Exceptional Children

The design of products should be usable by all people without the need for adaptation or specialized design for those with disabilities. This has been referred to as the Principle of Universal Design. It is assumed that if technology is designed to benefit all people, then individuals with intellectual disabilities will also benefit. Technology can impact the functional limitations and provide accommodations that will allow individuals with cognitive or intellectual disabilities to function in their daily environments. The Arc conducted a survey in 1995 that showed individuals with intellectual disabilities who needed technology but did not use it was greater than the number of respondents who had and used technology.


The authors used a meta-analysis of single subject design studies to determine if people with intellectual disabilities benefit from technology. Specifically, they were interested in determining if the principles of universal design benefit those with intellectual disabilities.


This study is a systematic review. The included studies were undertaken in various locations and settings. Settings included special education, residential setting, employment (1.8% of the studies), community settings, computer lab, multiple settings, and "other."


The sample consisted of 81 single-subject design studies that involved a total of 281 participants with intellectual and developmental disability. Participants ranged in age from 2 to 68 years. There were 169 males and 106 females with missing date for six participants.

Data Collection

The authors conducted an extensive search for articles published in peer-reviewed journals on the use of technology by people with intellectual disabilities from 1977 to 2003. They identified a total of 411 articles that were then coded and keywords identified such as inclusion, employment, education, recreation/leisure, and so forth. They also evaluated the degree to which the principle of universal design was discussed or identified as part of the features of the study. Of this number 275 articles were databased. The remaining were opinion or position statements. Of this number 251 were quantitative (group design, single-subject, literature reviews.) Of the quantitative studies, 81 implemented a single-subject design. These were the articles used in the meta-analysis. Each of the studies were examined for treatment efficacy.PND and PZD scores were calculated for each unique treatment phase and its preceding baseline identified in the cases. Data were summarized and reported in tabular and graphic formats. To examine the effect of individual characteristics and universal design features, separate ANOVAs were conducted with PND scores as dependent variables. The reliability of PND scores was assessed by using two independent raters. Reliability was calculated by dividing the number of agreements by the number of agreements plus disagreements, multiplied by 100 reaching 90% agreement.


Of these 81 articles, two-thirds were multiple-baseline design (n=54), 15% were ABAB reversal design (n=12), 10% used an AB design (n=8), and the remaining used some other design. Each of the studies were examined for treatment efficacy.


Forty percent of the articles had at least one universal design feature identified, and 60% used a device for which no UD feature was identified. Participants in the group incorporating UD features had an average PND score of 86% and those in the group not addressing UD features had an average PND score of 75%. Significant differences on PND scores emerged by level of severity of intellectual disability. Using ANOVA and post hoc analyses indicated differences between cases in which (a) participants had mild intellectual disabilities and cases in which participants had moderate or severe intellectual impairment, (b) cases in which participants had moderate intellectual disabilities and profound intellectual disability, and (c) cases in which participants had severe impairment and profound intellectual disability. No significant differences were found in PND scores by gender.


The authors concluded that additional research is needed on the efficacy of a wider range of technology devices with people with intellectual disability. Over 55% of the participants were evaluated with technology that fell into three types: computers, augmentative communication devices, and auditory prompting devices. If the next highest type of technology were added, video devices and switches, more than 70% of the participants were accounted for. In addition, three quarters of the participants were evaluated in segregated settings. The authors conclude that we know too little about the impact of technology on community-based settings. In addition, there were limited studies for employment meaning that the authors combined this area with other studies looking at independent living and leisure because there were not enough to be looked at separately. They conclude that it is evident "that we know very little about technology use and employment issues for people with intellectual disability in real employment settings."

Disabilities Intellectual disabilities
Populations Male & Female
Outcomes Other
Research Design Systematic reviews and meta-analysis
Peer Reviewed Yes