This paper investigates how student-workers' performance can be assessed through the notion of work-role performance, on the basis of three behavioral-related dimensions (proficiency, adaptivity, and proactivity), and proposes a definition of performance prior to graduation. By taking into account the accumulation of work experience, this article investigates first whether 1,310 cooperative education (co-op) students develop proficient, adaptive, and proactive performance behaviors toward the task and the team in the workplace and test the effect of the accumulation of work-experience of three cohorts. Second, it examines whether this work-role performance was different between 547 co-op students and 617 non-co-op students both with four months of work experience. Results showed that only team performance proficiency significantly increased with the accumulation of work experience for co-op students. Results did not show significant difference between co-op and non-co-op students with regard to work-role performance' scores.