Techniques derived from item response theory are useful for estimating the reliability of test classification above and below the cutting score. Test developers can construct a test whose information is peaked in the region of the cutting score; users can select a test which provides the most information in this region. The Cut-Score Characteristic Function (CSCF) mirrors the item response theory approach and can be used with observed scores. The test is arbitrarily divided in half, and the cut score is relocated. With a 100-item test having a cut score of 60, two 50-item tests are created, each having a cut score of 30. The scores for the first test are plotted on the x-axis of a graph, while the proportion who passed the second test is plotted on the y-axis. The resulting curves indicate a test (1) with high discriminating ability whose location matches the cut score reasonably well; (2) which matches the cut score, but does not discriminate as well; or (3) which discriminates well but is poorly matched to the cut score. This method emphasizes the test's quality in the region of the cut score. A test could be split into halves repeatedly. (GDC)