ABSTRACT
The present study meta-analytically compared coefficient alpha reliabilities reported for free and for-pay Big Five scales. We collected 288 studies from five previous meta-analyses of Big Five traits and harvested 1,317 alphas from these studies. We found that free and for-pay scales measuring Big Five traits possessed comparable reliabilities. However, after we controlled for the numbers of items in the scales with the Spearman-Brown formula, we found that free scales possessed significantly higher alpha coefficients than for-pay scales for each of the Big Five traits. Thus, the study offers initial evidence that Big Five scales that are free more efficiently measure these traits for research purposes than do for-pay scales.
Author Notes
Tyler Hamby, Ph.D., was a graduate student in the Department of Psychology at The University of Texas at Arlington at the time of the study. His research interests include psychometrics, survey methodology, and statistics.
Robert A. Peterson, Ph.D., is Associate Vice President for Research at The University of Texas at Austin and Director of the IC2 Institute there. His current research interests lie in the area of survey methodology.
Wyn Taylor, B.S., is a graduate student in the Department of Psychology at The University of Texas at Arlington. Her current research interests are psychophysiology and satisfying behavior.
Audrey K. Snowden, M.S., is a graduate student in the Department of Psychology at The University of Texas at Arlington. Her current research interests are in cognitive psychology.
Funding
This study was partly supported by Grant N000141310562 from the Office of Naval Research to T. Hamby.