What is a measurement device or technique used to quantify behavior?

The term that best describes a measurement device or technique used to quantify behavior is a psychological test. Psychological tests are structured methods used to assess various attributes, including intelligence, personality traits, and specific psychological conditions. They employ standardized procedures and scoring systems to ensure consistency and reliability in measuring individual differences in behavior and cognitive processes.

The utility of psychological tests lies in their ability to provide quantitative data, enabling practitioners to gauge and compare behavioral traits systematically. This comprehensive approach encompasses various test formats, such as self-reports, observational measures, performance tasks, and projective tests, thus allowing for an in-depth understanding of an individual's psychological profile.

While an assessment tool is a broader category that can encompass various methods, not all assessment tools are specifically psychological tests. Similarly, a behavioral scale is focused on evaluating particular behaviors and is typically part of a larger testing framework, whereas an observation checklist is primarily a qualitative method for recording specific behaviors as they occur in real time. These distinctions highlight why a psychological test precisely encapsulates the concept of a measurement device or technique designed to quantify behavior.