Development of the Exam of GeoloGy Standards, EGGS, to Measure Students' Conceptual Understanding of Geology Concepts

Discipline-based geoscience education researchers have considerable need for criterion-referenced, easy-to-administer and easy-to-score, conceptual diagnostic surveys for undergraduates taking introductory science survey courses in order for faculty to better be able to monitor the learning impacts of various interactive teaching approaches. To support ongoing discipline-based science education research to improve teaching and learning across the geosciences, this study establishes the reliability and validity of a 28-item, multiple-choice, pre- and post- Exam of GeoloGy Standards, hereafter simply called EGGS. The content knowledge EGGS addresses is based on 11 consensus concepts derived from a systematic, thematic analysis of the overlapping ideas presented in national science education reform documents including the Next Generation Science Standards, the AAAS Benchmarks for Science Literacy, the Earth Science Literacy Principles, and the NRC National Science Education Standards. Using community agreed upon best-practices for creating, field-testing, and iteratively revising modern multiple-choice test items using classical item analysis techniques, EGGS emphasizes natural student language over technical scientific vocabulary, leverages illustrations over students' reading ability, specifically targets students' misconceptions identified in the scholarly literature, and covers the range of topics most geology educators expect general education students to know at the end of their formal science learning experiences. The current version of EGGS is judged to be valid and reliable with college-level, introductory science survey students based on both standard quantitative and qualitative measures, including extensive clinical interviews with targeted students and systematic expert review.