Which term describes the designation of responses as members of the target class by their environmental effect?

• A. Direct Measurement
• B. Discontinuous Measurement
• C. Functional Definition of Behavior
• D. Dependent Variable

Answer: (C)

Describing a response by the effect it has on the environment is a functional definition of behavior. It means you define what counts as the target behavior not by how it looks, but by what it accomplishes—such as gaining attention, escaping a demand, or obtaining a preferred item. This allows all forms that serve the same function to be included in the same class, which is crucial for identifying and changing the environmental contingencies that maintain the behavior. Measurement-related terms like direct measurement, discontinuous measurement, or dependent variable describe how we observe or quantify behavior, not how we classify it by its function.