Evaluation of the reliability and validity of GraphClick as a data extraction program

Data extraction programs are used to obtain approximations of raw data from published graphs. Quantitative syntheses of single-subject data require that researchers have access to valid and reliable data extraction programs. We analyzed the reliability and validity of a data extraction program, GraphClick. Three independent coders extracted data from 191 graphs from the Journal of Applied Behavior Analysis (JABA) and 15 graphs of hypothetical data. Results showed that GraphClick is both reliable and valid with nearly perfect correlations for all analyses. Suggestions are included for researchers and authors to improve the accuracy of data extraction techniques.