Traditionally, self-efficacy (SE), or the confidence in one's capability to execute a task, is measured using pre/post-surveys to demonstrate shifts in students' SE. In this work, we present a preliminary analysis of a single student drawing on a mixed methods approach to examine how their SE fluctuates over time. This novel design employs the Experience Sampling Method, a quantitative technique using surveys of domain-specific self-efficacy, and daily reflections, a qualitative technique investigating threats and supports towards students' SE. The preliminary analysis was broken into two strands: (1) using interquartile range (IQR) to define low, normal, and high SE for a student based on their survey scores, and (2) using the student's daily journal reflection responses as proof of concept for defining the student's SE as low, normal, or high from the IQR analysis of survey responses. Findings indicate the boundaries of a student's IQR can define high, normal, and low SE and the student's responses to the daily journal prompts corroborates these definitions.