The ability of a test to measure what is purports to measure is to ; that which is to the consistency of test results.

The correct answers are validity; reliability.

Answer 1: The ability of a test to measure what is purports to measure is called validity. Validity is defined as the ability of a test or study to actually to measure what it claims to measure. For instance, if a test aims to measure a population sample's heart rate, but ends up measuring blood sugar levels instead, it does not have validity, since it did not measure what it claimed or set out to measure. 

Answer 2: Reliability refers to the consistency of test results. Reliability can be defines as the ability of a test or measure to consistently produce the same results at different, times, settings or locations. If the same test or measure produces different outcomes or results at different times or locations, it is low in reliability.