  The Modeling Instruction (MI) approach to introductory physics manifests
significant increases in student conceptual understanding and attitudes toward
physics. In light of these findings, we investigated changes in student
self-efficacy while considering the construct's contribution to the
career-decision making process. Students in the Fall 2014 and 2015 MI courses
at Florida International University exhibited a decrease on each of the sources
of self-efficacy and overall self-efficacy (N = 147) as measured by the Sources
of Self-Efficacy in Science Courses-Physics (SOSESC-P) survey. This held true
regardless of student gender or ethnic group. Given the highly interactive
nature of the MI course and the drops observed on the SOSESC-P, we chose to
further explore students' changes in self-efficacy as a function of three
centrality measures (i.e., relational positions in the classroom social
network): inDegree, outDegree, and PageRank. We collected social network data
by periodically asking students to list the names of peers with whom they had
meaningful interactions. While controlling for PRE scores on the SOSESC-P,
bootstrapped linear regressions revealed post-self-efficacy scores to be
predicted by PageRank centrality. When disaggregated by the sources of
self-efficacy, PageRank centrality was shown to be directly related to
students' sense of mastery experiences. InDegree was associated with verbal
persuasion experiences, and outDegree with both verbal persuasion and vicarious
learning experiences. We posit that analysis of social networks in active
learning classrooms helps to reveal nuances in self-efficacy development.
