Statistics for People Who (Think They) Hate Statistics

by Neil J. Salkind

In general, if you don’t have the validity evidence you want, then it’s because your test is not doing what it should. If it’s an achievement test and a satisfactory level of content-based validity is what you seek, then you probably have to rewrite the questions on your test to make sure they are more consistent with the opinions of the experts you consulted or with the state board of education’s standards for what should be taught at each grade level. If you are concerned with criterion-based validity, then you probably need to reexamine the nature of the items on the test and answer the question, How well do I expect these responses to these questions to relate to the criterion? And, of course, this assumes that the criterion you are using makes sense. And finally, if it is construct-based validity that you are seeking and can’t seem to find, then you better take a close look at the theoretical rationale that underlies the test you developed. Perhaps your definition and model of aggression are wrong, or perhaps the definition and conceptualization of intelligence need some critical rethinking. Your aim is to establish consistency between the theory and the test items based on the theory.