Reliability is necessary but not sufficient for validity. The validity of a test tells us how well the test measures what it is supposed to measure. Your intelligence could be reliably assessed by your height, but that would not be valid. The defined content domain is well sampled. E.g., the SAT is supposed to have a moderately high level of criterion-related validity because it is a good predictor of achievement in college.
Theories are only models of the world.
Construct validity is relevant to assessing the adequacy of a measure intended to capture a theoretical abstraction. Norms Because psychological measurement is relative, test scores are usually interpreted by comparison to the scores of others. Norms summarize the scores of a defined group, used for the purpose of comparison. Usually, we are interested in a population , which is represented by a sample . Norms are almost always derived from the scores of the sample, to represent the scores of the population.