Self-efficacy has been shown to be central to student motivation (Bandura, 1999), and within self-determination theory feelings of competency are considered to be fundamental to human well-being (Ryan & Deci, 2017). This paper introduces a longitudinal study conducted in a tertiary educational context in Japan that measured changes in students’ English speaking self-efficacy over the course of one academic year. A measure of self-efficacy was developed and administered on eight separate occasions to three groups of students taking part in an oral English course. Potential predictors of change in self-efficacy were also measured, and hierarchical linear modeling was used to assess the model for growth. Students were also interviewed to determine their views on self-efficacy and perceptions of change. Self-determination theory was used as a framework for interpreting the results, which showed that self-efficacy grew over time for all students, and can be fostered by providing students with mastery experiences within the classroom. The results suggest that reasonably large gains in self-efficacy are possible in a short time, but also that is it necessary to continually provide challenging and yet achievable tasks for students to maintain growth. Students who began the study with higher levels of proficiency made fewer gains in self-efficacy, suggesting that they perceived the tasks to be relatively simple. For these students, tasks did not contribute as significantly to feelings of mastery. The pedagogical implications of the research are discussed.
Keywords: Speaking, Self-efficacy, Self-determination theory;