Which of the following refers to the assurance that a measurement is consistent over time?

The concept that refers to the assurance that a measurement is consistent over time is reliability. In research, reliability is crucial because it indicates the stability and consistency of a measurement tool or instrument. This means that when repeated measurements are taken under the same conditions, a reliable measurement will yield the same results.

For example, if a psychological test is administered to the same group of individuals on two separate occasions and the results are similar, then the test is considered reliable. High reliability is vital for ensuring that conclusions drawn from the data are based on precise and dependable measurements rather than random errors or fluctuations.

In contrast, validity refers to the extent to which a measurement actually measures what it claims to measure. Trustworthiness can relate to qualitative research, indicating the credibility of the findings but is not specifically focused on measurement stability. Accuracy relates to how close a measurement is to the true value rather than its consistency over time. Thus, reliability is the appropriate term for the consistency of a measurement.