Wednesday, May 7, 2008

Why “Good” Schools Need “Bad” Schools

Good schools need bad schools. That is one reason education reform cannot work. Here-today-gone-tomorrow education fads give the appearance of constant effort, keeping researchers employed, giving administrators something to implement, and making busy teachers even busier. These fads, masquerading as reform efforts, deflect attention from the need to maintain bad” schools for the benefit of “good” schools.

Standardized tests drive this strange relationship. Most standardized tests are norm-referenced as opposed to criterion-referenced. Norm-referenced tests compare the test taker to the whole population of test takers. Criterion-referenced tests compare the test taker to a set of criteria.

Therefore, norm-referenced tests often express the score in terms of percentile. For example, if you score at the 85th percentile, it means you did better than 85 percent of the test takers. By definition, the 50th percentile means that half the test takers did better than the other half, and half the test takers did worse than the other half. Percentile deems the median to be the average. It does not matter how well a student learned or how well the teacher taught, half of the students are destined to be "below average" on a norm-referenced test (like nearly all standardized tests). Therefore the main problem with percentile is that the existence of a schools with above average performance necessitates the existence of schools with below average performance. It is impossible for all boats to rise.

A second problem with norm-referencing is the inherent competition. Academic achievement is an individual, personal achievement, or should be. All children have the potential to improve their academic achievement; all boats have the potential to rise. Norm-referencing undermines that potential. A third problem with norm-referencing is that it can actually disguise truly poor performance with a mask of apparent excellent performance. A bad score could be better than the 95% worse scores. A misleadingly high percentile could give the test taker a false sense of their performance. A fourth problem is that not all norm-referenced tests are expressed as percentiles. A good example is SAT tests which seem to be in terms of an actual score, but actually the scores are recalibrated periodically to ensure the mean and the median are the same.

Research has shown that time on task under the guidance of a skilled teacher is the major determinant of academic achievement. Every test reduces instructional time. It is ironic that so-called experts who should know better recommend more testing as the answer. Classroom teachers do not need tests to know how their students are doing. The system, however, does require some nominally “objective” measure of student performance. Maybe we can live with some tests; what we do not need is more tests, especially more norm-referenced tests.

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