The Anchoring Hypothesis and the Illusion of Learning: Why High-Performing Practice Students Underperform on High-Stakes Assessments

Abstract

Abstract

We report a counterintuitive pattern across four sections of an introductory biology course (N = 73): students who scored well on adaptive practice quizzes (M = 87.8%) subsequently scored substantially lower on course examinations (M = 54.1% overall), a mean discrepancy of about 34 percentage points that was larger still among the lowest-performing group. We describe this pattern as a possible Illusion of Learning: adaptive learning systems may reward recognition and pattern-matching while providing limited information about a student's capacity for conceptual integration and transfer. To account for the pattern, we propose the Anchoring Hypothesis, a testable model in which durable performance in biology depends not only on acquiring facts but on integrating them within a coherent conceptual framework. Across the combined cohort, the gap between practice and examination performance was larger for lower-performing students (about 43 points) than for higher-performing students (about 14 points), t(34) = 5.03, p < .001. A brief, two-level conceptual pretest was associated with examination performance, r = .26, p = .032. These findings are consistent with the Anchoring Hypothesis and generate specific predictions for future, adequately powered, and causally-informative research. Because the data are observational, drawn from one course and institution in one semester, and because the pretest was a coarse (two-level) measure, we treat all conclusions as preliminary.