Define reliability and validity, and explain how they relate to one another using the analogy of a dartboard or target.

What will be an ideal response?

Reliability refers to the consistency of an assessment process; a measure or assessment must perform the same from use to use in order to be reliable. Validity refers to the accuracy of an assessment process; the measures and assessments must be measuring what they claim to be measuring. Although the two concepts are independent of one another, reliability usually precedes validity: An unreliable measure (something that doesn’t measure consistently in the first place) is unlikely to be valid (it therefore doesn’t matter what it measures, because it doesn’t measure anything very well). An analogy to a target is helpful. Shots that hit the target haphazardly are neither reliable nor valid; there’s no consistency and little accuracy. Shots that cluster closely together off-center are reliable but not valid; the hits are very consistent, but not in the center of the target (i.e., not accurate). Shots that hit a target dead-center are both reliable and valid; they consistently hit the middle of the target, and the middle of the target represents an accurate outcome.