The "Lake Wobegon" Effect: How Can Most Students Be Above Average?

Lake Wobegon is radio humorist Garrison Keillor's mythical town in Minnesota where "all the women are strong, all the men are good looking, and all the children are above average." John Jacob Cannell, M.D., borrowed the name to describe the puzzling fact that school districts across the country have reported their students as above average. On standardized achievement tests, Dr. Cannell discovered, more than 90 percent of the 15,000 elementary school districts and 80 percent of the secondary school districts in the nation reported scores above the national norm instead of the expected 50 percent. How could this be? Dr. Cannell has several explanations.

First, norm-referenced achievement tests compare current student achievement with the achievement of a norm group tested in the past. Current national averages are not computed. The norm groups are supposed to represent an average group of students tested under conditions similar to those used in current testing programs. Dr. Cannell points out, however, that unlike currently tested students, norm groups are "tested cold" without any prepping on exact test questions and without having their curriculum "aligned" with the test questions. The result is that the high scores reported by many school districts, although higher than the norm group scores, are not necessarily higher than the average of all students currently taking the tests.

Dr. Cannell further charges that because educators are under such tremendous pressure to raise test scores, they sometimes resort to such practices as changing student answers, allowing more time to complete the test, distributing advance copies of the test, and excluding special education and bilingual students from testing. By excluding "at-risk" students from achievement testing, some school districts artificially inflate achievement test scores. Dr. Cannell's charges have led to a serious examination of practices in the use of norm-referenced achievement tests.

Source: John Jacob Cannell, How Public Educators Cheat on Standardized Achievement Tests (Albuquerque: Friends of Education, 1989).