DETERMINING THE EFFICACY OF INTERVENTION - THE USE OF EFFECT SIZES FOR DATA-ANALYSIS IN SINGLE-SUBJECT RESEARCH

Use of the effect size as a descriptive statistic for single-subject r esearch is presented, A brief review of visual and statistical analysi s techniques commonly used in single-subject methods is provided, and the limitations of each are noted. Effect sizes are presented as stati stics that can augment the interpretation of results as well as provid e additional information about the effectiveness,of interventions. Fou r types of treatment effects are presented, with corresponding case st udies illustrating the computation and interpretation of the effect si ze for each. An appendix includes the case study data and a sample com puter program for computing the effect sizes described.