Standardized tests are particularly useful for making comparisons. They let us compare a person's ability at one time to that person's ability at a second time, as in pre-and post-testing. They also permit comparisons among programs. However, for the tests to give valid results for making such comparisons, they must be administered according to the standard conditions.

By understanding the logic of standardization in testing, programs can strive to keep the conditions of test administration from affecting test performance. Here are some things to avoid:

Avoid: Ignoring time standards. Here is a simple illustration of the reasoning behind the methodology of standard conditions. If a program wanted to compare a group of learners' post-program reading ability to their pre-program ability, and it only gave them fifteen minutes to complete a hundred items on the pre-test, then it would not be appropriate to let them have thirty minutes to complete a comparable set of items at the post-test. Using such different conditions of test administration, one could not infer that the learners' greater post-test scores indicated a true gain in ability over the pre-test scores. It might simply indicate that the learners were able to complete more items because there was more time. In this case, then, the learners' abilities had not increased. Rather, the conditions under which the test was administered were changed. They were not standard for both the pre- and the post-tests. And these changed conditions of administration may have produced the observed increase in test scores.

Avoid: Testing the first time students show up for a program. Many adult students will not be very comfortable at the first meeting. They may be nervous and frightened about taking a test. They may also be unprepared in test-taking strategies. Because of this psychological condition of the learner, they do not meet the conditions of standardization of most tests, which assume a more-or-less relaxed, test-experienced learner. If pre-tested under their first meeting psychological conditions, learners' true abilities may be greatly underestimated. Then, at the post-test, after they have had time to adjust to the program, its staff, and have had practice in answering test questions similar to the standardized tests, their post-test scores may be higher. But in this case, much of the gain may represent the change in the learners' emotional conditions, and not gain in the cognitive ability (e.g., reading, writing, mathematics) that is the object of assessment.

The increase in post-test scores over pre-test scores due to the kinds of psychological factors discussed are sometimes called "warm-up," "surge" or "practice" effects. Such effects may be particularly troublesome when pre- and post-testing are separated by only a few hours. Some programs may have capitalized on such effects in claiming to make one, two or more "years" gain in reading or mathematics in just 15 or 20 hours of instruction. In general, pre-testing should not be accomplished until learners have had an opportunity to adjust to the program and practice their test-taking skills.