Kong, XiuyuanMcEwan, James S.A.Bizo, Lewis A.Foster, T. Mary2017-04-2120172017-04-212017Kong, X., McEwan, J. S. A., Bizo, L. A., & Foster, T. M. (2017). An analysis of U-Value as a measure of variability. The Psychological Record, -online, 1–6. https://doi.org/10.1007/s40732-017-0219-20033-2933https://hdl.handle.net/10289/11009The variability in behavior has frequently been assessed using a measure known as the U-value. Of concern in this article were the limits and constraints on U-value as a measure of variability. The relation between the U-value and aspects of variability was examined using three sets of simulated data. Our analysis demonstrates that the U-value as a measure of variability on its own fails to capture repetitive patterns in the sequence of responding. The U-value was shown to reflect the evenness of the distributions of responses across the categories/options used; however, when the number of categories actually used by the participant differed from the total number available, the relation between U-values and the number of categories allocated with responses was shown to be nonlinear. It was also shown that the same value of U can represent different levels of evenness in response distributions over categories, depending on the number of categories/options actually used. These constraints and limitations are discussed in relation to how researchers might report on behavioral variability.application/pdfapplication/vnd.openxmlformats-officedocument.wordprocessingml.documentapplication/vnd.openxmlformats-officedocument.wordprocessingml.documentimage/jpegapplication/vnd.openxmlformats-officedocument.wordprocessingml.documentapplication/vnd.openxmlformats-officedocument.wordprocessingml.documenten© Association for Behavior Analysis International 2017. This is the author's accepted version. The final publication is available at Springer via dx.doi.org/10.1007/s40732-017-0219-2Behavioral variabilityMeasure of variabilityStereotypyU-valueJournal Article10.1007/s40732-017-0219-22163-3452