Educational tests are standardized so that all examinees are tested on the same material, under the same testing conditions, and with the same scoring protocols. This uniformity is designed to provide a level "playing field" for all examinees so that the test is "the same" for everyone. Thus, standardization is designed to promote fairness in testing. In practice, the material tested, the conditions under which a test is administered, and the scoring processes, are often too rigid to provide the intended level playing field. For example, standardized testing conditions may interact with personal characteristics of examinees that affect test performance, but are not construct-relevant. Thus, more flexibility in standardization is needed to account for the diversity of experiences, talents, and handicaps of the incredibly heterogeneous populations of examinees we currently assess. Traditional standardization procedures grew out of experimental psychology and psychophysics laboratories where keeping all conditions constant was crucial. Today, accounting for and measuring what is not constant across examinees is crucial to valid construct interpretations. To meet this need I introduce the concept of "understandardization," which refers to ensuring sufficient flexibility in standardized testing conditions to yield the most accurate measurement of proficiency for "each" examinee.