Hydrogeology Concept Inventory

Concept inventories are comprised of statistically validated multiple-choice items that measure knowledge in a specific domain. In the geosciences, existing inventories measure student understanding of introductory geoscience, oceanography, astronomy, meteorology, and mineralogy, but no concept inventory exists for hydrogeology. Through an iterative process involving expert review, instructor feedback, analysis of student interviews and open-ended written responses, and quantitative analysis, we developed a 20-item hydrogeology concept inventory (HCI) that assesses student knowledge of 11 key concepts commonly taught in introductory hydrogeology courses (typically taken by upper-level undergraduate students). As part of the validation process, 19 instructors reviewed the first version of the HCI and reported that 77% of the concepts were related to their course content, that these concepts were extremely to moderately important in their courses, and that each item measured its related concept moderately to very well. We evaluated the instrument’s psychometric properties in a sample of 142 students enrolled in introductory hydrogeology courses across U.S. and Canada using metrics drawn from both Classical Test Theory (CTT) and Item Response Theory (IRT). Both testing theories and qualitative development methods were used to establish the face, content, and construct validity of the HCI as well as its reliability with the tested student population. Additionally, we used the selection frequency of functional distractors to identify potential misconceptions among this sample of students. Here we share how the HCI was developed as well as its potential uses as a research instrument or teaching assessment in introductory hydrogeology courses.