The Source of Lake Wobegon [updated]

The Source of Lake Wobegon

John J. Cannell's late 1980's “Lake Wobegon” reports suggested widespread deliberate educator manipulation of norm-referenced standardized test (NRT) administrations and results, resulting in artificial test score gains. The Cannell studies have been referenced in education research since, but as evidence that high stakes (and not cheating or lax security) cause test score inflation. This article examines that research and Cannell's data for evidence that high stakes cause test score inflation. No such evidence is found. Indeed, the evidence indicates that, if anything, the absence of high stakes is associated with artificial test score gains. The variable most highly correlated with test score inflation is general performance on achievement tests, with traditionally low-performing states exhibiting more test score inflation—on low-stakes norm-referenced tests—than traditionally high-performing states, regardless of whether or not a state also maintains a high-stakes testing program. The unsupported high-stakes-cause-test-score-inflation hypothesis seems to derive from the surreptitious substitution of an antiquated definition of the term “high stakes” and a few studies afflicted with left-out-variable bias. The source of test-score inflation is lax test security, regardless the stakes of the assessment.

What causes test-score inflation? Comparing two theories

Teaching to the test: A very large red herring

The Source of Lake Wobegon [slide show]

The Rocky Score-line of Lake Wobegon

Measuring up: What educational testing really tells us. (book review)

The Source of Lake Wobegon

The Source of Lake Wobegon [Updated] (pdf file)

The Source of Lake Wobegon [original]