In response to calls for engineering programs to better prepare students for future careers, many institutions offer courses with a design component to first-year engineering students. This work proposes that traditional exam-based assessments of design concepts are inadequate, and alternative forms of assessment are needed to assess student learning in design courses. This paper investigates the self-efficacy differences between a traditional exam and a two-part practicum as a mid-semester assessment for introductory engineering students enrolled in a first-year design course. Increased self-efficacy has been linked to various positive student outcomes and increased retention of underrepresented students. The practicum consisted of an in-class team design task and an out-of-class individual reflection, while the exam was a traditional, individual written exam. All students completed a pre-assessment survey and a post-assessment survey, both of which included measures of design self-efficacy. Analysis showed that the practicum increased the design selfefficacy of students more effectively than the exam. Students who identified as women had greater gains in design selfefficacy during the practicum as compared to men. Identifying as a minority subgroup student was also trending towards being a significant predictor of change in self-efficacy for the practicum. Findings suggest that a mid-semester practicum is a successful assessment of design competencies that contributes to increased first-year engineering student self-efficacy.