title: The genetic drift inventory: a tool for measuring what advanced undergraduates have mastered about genetic drift.
abstract: Understanding genetic drift is crucial for a comprehensive understanding of biology, yet it is difficult to learn because it combines the conceptual challenges of both evolution and randomness. To help assess strategies for teaching genetic drift, we have developed and evaluated the Genetic Drift Inventory (GeDI), a concept inventory that measures upper-division students' understanding of this concept. We used an iterative approach that included extensive interviews and field tests involving 1723 students across five different undergraduate campuses. The GeDI consists of 22 agree-disagree statements that assess four key concepts and six misconceptions. Student scores ranged from 4/22 to 22/22. Statements ranged in mean difficulty from 0.29 to 0.80 and in discrimination from 0.09 to 0.46. The internal consistency, as measured with Cronbach's alpha, ranged from 0.58 to 0.88 across five iterations. Test-retest analysis resulted in a coefficient of stability of 0.82. The true-false format means that the GeDI can test how well students grasp key concepts central to understanding genetic drift, while simultaneously testing for the presence of misconceptions that indicate an incomplete understanding of genetic drift. The insights gained from this testing will, over time, allow us to improve instruction about this key component of evolution.
authors.affiliation: School of Interdisciplinary Arts and Sciences, University of Washington, Bothell, Bothell, WA 98011 Department of Biology, University of Wisconsin-La Crosse, La Crosse, WI 54601.
authors.forename: Rebecca M
authors.initials: RM
authors.lastname: Price
authors.forename: Tessa C
authors.initials: TC
authors.lastname: Andrews
authors.forename: Teresa L
authors.initials: TL
authors.lastname: McElhinny
authors.forename: Louise S
authors.initials: LS
authors.lastname: Mead
authors.forename: Joel K
authors.initials: JK
authors.lastname: Abraham
authors.forename: Anna
authors.initials: A
authors.lastname: Thanukos
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Perez
mesh_terms: D000047:Academies and Institutes; D032882:Comprehension; D003210:Concept Formation; D003479:Curriculum; D004521:Educational Measurement; D040961:Genetic Drift; D005823:Genetics / Q000193:education*; D013334:Students; D011795:Surveys and Questionnaires