Effects of functional communication training for reducing challenging behaviours of nonverbal individuals with developmental disabilities

Although previous narrative reviews have found functional communication training to be an effective intervention to reduce aberrant behaviour, until now, there has not been sufficient data to statistically analyze the various parameters. The current meta-analysis used a regression approach (Center, Skiba & Casey, 1985-1986) to objectively and systematically compare findings across single-case studies in an empirical fashion to examine the growing body of literature demonstrating the effectiveness of functional communication training for nonverbal individuals with developmental disabilities who engage in aberrant behaviour. Fifteen primary research studies generated a total of 76 baseline/treatment comparisons which resulted in 228 effect sizes. The effect sizes were used as the dependent variable in the analysis. The 7 parameters under investigation were: 1) diagnosis/type of disability, 2) form of behaviour, 3) function of behaviour, 4) alternative communicative response, 5) setting, 6) maintenance, and 7) generalization. Analysis on subject sex, primary disability and preintervention mode of communication were also examined. The findings indicated that functional communication had a significant impact on reducing challenging behaviours of nonverbal individuals with various developmental disabilities and was equally effective across all parameters except for the function of behaviour, alternative communicative response, and pre-intervention mode of communication. Additional analyses were conducted on the assessment method, treatment design and treatment package. Results indicated that effectiveness varied depending upon the form of assessment that was used prior to intervention. The analyses also indicated a significant 2-way interaction between the assessment method prior to intervention and the treatment package. Methodological characteristics and their implications for both research and practice as well as areas for future research are discussed.Education, Faculty ofEducational and Counselling Psychology, and Special Education (ECPS), Department ofGraduat