An operational definition is best described as:

• A. A broad theoretical description
• B. A precise description of how a variable will be measured
• C. A schematic diagram of an experiment
• D. A literature review method

Answer: (B)

Operational definitions specify exactly how a variable will be measured or manipulated in a study. This precision is essential because it translates an abstract idea into concrete, observable steps that others can replicate. In addiction research, for instance, if you’re studying craving, an operational definition might specify measuring craving on a standardized 0–10 scale during a defined time frame, or counting the number of self-reported urges per day using a structured diary. This level of detail makes findings reliable and comparable across studies.

The other descriptions don’t fulfill that measurement-focused role. A broad theoretical description explains the concept in general terms rather than how to observe it. A schematic diagram outlines experimental procedures or flow but not the specific measurement of a variable. A literature review method concerns how researchers search and synthesize existing studies, not how a variable is defined and measured in a study.