An operational definition of a psychological construct that is conceptually unrelated to the construct results in the measure not being:

The answer to this question is: Valid

For example, let's say that a researcher wants to study the psychology of motivation as a variable.

In this case, motivation does not possess a measurable standard that could be used as data, so the researcher could only predict thte amount of motivation through the amount of job done (but this data is reliable because motivation is only on of the many factors that may influenced it)