Final answer:
Construct validity is a measure of how well a test or experiment reflects the underlying theoretical constructs it is supposed to measure, which is crucial for ensuring that results are not just consistent, but accurate reflections of the concepts being investigated.
Step-by-step explanation:
Construct validity is a method of evaluating validity by assessing how well the measurement captures the construct or concept under consideration and how well it logically connects to underlying theories. In essence, construct validity determines whether an instrument measures the construct it was designed to measure. This ties into the broader issue of validity, which is the accuracy of a given result in measuring what it is designed to measure. Validity comes in various forms, including ecological validity, face validity, and others, but construct validity is specifically concerned with the theoretical backing and the measurement's ability to actually reflect that theory.
Researchers often develop an operational definition for each concept, which is a way to define the variable in concrete, measurable terms, ensuring the study validly represents the phenomenon in question. While a measure can be reliable but not valid, a valid measure must also be reliable, meaning it produces consistent, reproducible results.