Final answer:
A measure that is consistent on the same individual on separate occasions is demonstrating test-retest reliability, which is different from internal validity, construct validity, or inter-rater reliability. Reliability refers to consistency, while validity refers to accurate measurement of the intended concept.
Step-by-step explanation:
If a measure is consistent on the same individual on separate occasions, it is demonstrating test-retest reliability. This concept is one of the aspects of reliability, which refers to the ability of a measurement method to produce stable and consistent results across multiple occasions of measurement. In contrast, internal validity refers to the extent that a study accurately reflects or assesses the specific concept that the researcher is attempting to measure. Construct validity involves whether a tool is measuring what it is designed to measure, and inter-rater reliability refers to the level of agreement among different raters or observers.
There's an important distinction between reliability and validity that is crucial in research. While a method might be reliable, as in giving consistent results, it might not necessarily be valid, which concerns the accuracy of the measurement regarding the concept it's intended to measure. This is why researchers aim for both high reliability, including test-retest reliability, and high validity in their measurement tools.