| This dissertation includes four studies investigating the overarching question: How do interest, skills, and ability influence people's choice of the geosciences for careers, generally, and performance on earth science assessments, specifically? The first study involves interviews with 37 field geologists. Three major themes emerged that focused on (1) academic experiences, typically at the undergraduate level, (2) relationships with people such as family, professors, and peers, and (3) transformative experiences with the Earth through local geology, fossils, museums, maps, or other objects. The second study is an analysis of visual representations appearing on a set of standardized science assessments. The study uncovered that the type of visuals appearing on the New York State Regents exams for living environment (biology), earth science, chemistry, and physics assessment vary substantially between the science disciplines. The earth science assessment had the greatest number and variety of visuals. The third and fourth chapters are studies of earth science assessment data from 144 high school students from two high schools in New York State. The third study explores the relationship between item format and student performance as well as overall content validity using classical test theory and Rasch analysis. The test included three item formats: (1) text only, (2) visuals and text, and (3) items containing visuals for which students have been trained during their course. Items containing visual representations that were novel for the students were found to be the most difficult and best discriminating items for the sample population. Items that required the Earth Science Reference Tables (ESRT), and therefore students had prior training, were the easiest questions for the sample, however they still provided good discrimination among lower performing students. The fourth study includes a path analysis of the direct and indirect effects of sex, reading comprehension, spatial ability, motivation, and prior knowledge on the Earth Science Regents exam. The exam items were split into three subscales based on the item format described in chapter three. Spatial ability was a significant predictor of student performance on questions with novel visuals but not on questions with trained visuals from the ESRT. The studies in this dissertation found that interest is developed through academic experiences, people, and experiences with the Earth. Visual representation skills are important since a greater number and wider variety of visual representations are used in the geosciences than other science fields. Spatial ability is linked to performance on visual representations on the earth science assessments. |
