On Terms: Frequency and Rate in Applied Behavior Analysis

Abstract

The term "frequency" in applied behavior analysis and behavior measurement generally refers to cycles per unit time, or a count (usually of behavior) divided by the time during which it occurred. In statistics, however, the term refers to a count of items in a data set. This meaning of "frequency" as synonymous with "count" has been adopted by one major text and the Behavior Analyst Certification Board®. Another major text uses "frequency" and "rate" interchangeably when referring to behaviors per unit time. Both texts advise readers not to use counts of behavior without reference to the time base of the observation, and in the context of that advice, the count and time information thus provide rate data. We suggest that within applied behavior analysis (ABA) and behavior measurement the term "frequency" should not refer to "count" but instead to "rate," and that references to counts without information about observation time should be avoided.