Thesis advisor: Michael Russell / This paper describes the construct of fascination in science, a non-cognitive trait combining interest, curiosity, and mastery skills, and the particular relevance of fascination in science for students during middle school. Grounded in the theory of Science Learning Activation and employing data from the longitudinal Activated Learning Enables Success study of 2014 (ALES:14), cohorts of sixth and eighth graders were measured on fascination five times over two school years, allowing for an investigation of change over time. Multilevel models were constructed for each grade-level cohort in an effort to determine patterns of change, while also testing for relationships with several student-level characteristics and class-level instructional variables. Results suggest discontinuous patterns of change in fascination, with declining fascination scores in grade 6 boosted over the summer break and declining fascination scores in grade 8 rising the following school year. While the impact of instructional variables was negligible, relationships with several individual covariates were observed, primarily indicating the importance of family support for science. Future research should focus on context-specific elements of in-school activities, along with additional out-of-school factors that may influence fascination. / Thesis (PhD) — Boston College, 2022. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Research, Measurement and Evaluation.