Using and updating local norms

The most useful kind of norms are local norms collected by a test interpreter on a population with which s/he is familiar. We present a rationale for the use of local norms and a procedure, illustrated with an example, for updating a norm group's test score mean and variance. It was concluded that test interpreters should build local norms to be used in conjunction with norms based on a national sample, since local norms can be more recent, relevant, and representative for local groups.