outcomes in many ways. This is important because the use of incentives for performance on tests is likely to reduce emphasis on the outcomes that are not measured by the test.
The academic tests used with test-based incentives obviously do not directly measure performance in untested subjects and grade levels or development of such characteristics as curiosity and persistence. However, those tests also fall short in measuring performance in the tested subjects and grades in important ways. Some aspects of performance in many tested subjects are difficult or even impossible to assess with current tests. And even for aspects of performance that can be tested, practical constraints on the length and cost of testing make it necessary to limit the content and types of questions. As a result, tests can measure only a subset of the content of a tested subject.
When incentives encourage teachers to focus narrowly on the material included on a particular test, scores on the tested portion of the content standards may increase while understanding of the untested portion of the content standards may stay the same or decrease. To the extent feasible, it is important to broaden the range of material included on tests to better reflect the full range of what students are expected to know and be able to do. And it is important to remember that the scores on the tests used with incentives may give an inflated picture of learning with respect to the full range of the content standards.
Incentives for educators are rarely attached directly to individual test scores; rather, they are usually attached to an indicator that combines and summarizes those scores in some way. Attaching consequences to different indicators created from the same test scores can produce dramatically different incentives. For example, an indicator constructed from average test scores or average test score gains will be sensitive to changes at all levels of achievement. In contrast, an indicator constructed from the percentage of students who meet a performance standard will be affected only by changes in the achievement of the students near the cut score defining the performance standard.
Given the broad outcomes that are the goals for education, the necessarily limited coverage of tests, and the ways that indicators constructed from tests focus on particular types of information, it is prudent to consider designing an incentive system that uses multiple performance measures. Incentive systems in other sectors have evolved toward using increasing numbers of performance measures on the basis of their experience with the limitations of particular performance measures. Over time, organizations look for a set of performance measures that better covers the full range of desired outcomes and also monitors behavior that would merely inflate the measures without improving outcomes.