Any of a set of test forms, all of which are statistically the same in terms of content areas covered as well as the number and difficulty of the items included. Each form may contain unique items. Equivalent forms are designed to yield directly comparable scores for a given group. Also called a parallel or alternate form.

Norms that are estimated beyond the standardization windows in which a test was actually administered. Extrapolated norms allow for accurate score interpretations when tests are administered during periods of the school year for which empirical data was not collected. See also norms.