A survey incorporating qualitative measures of student self-efficacy beliefs was administered to 1,387 first-year engineering students enrolled in ENGR 106, Engineering Problem-Solving and Computer Tools, at Purdue University. The survey was designed to identify factors related to students' self-efficacy beliefs, their beliefs about their capabilities to perform the tasks necessary to achieve a desired outcome. Open-ended questions prompted students to list factors affecting their confidence in their ability to succeed in the course. Students were then asked to rank these factors based on the degree to which their  self-efficacy beliefs were influenced. Gender trends emerged in student responses to factors that affect confident in success. These trends are discussed in light of the categories identified by efficacy theorists as sources of self-efficacy beliefs. The results presented here provide a useful look at the first-year engineering experiences that influence students' efficacy beliefs, an important consideration in explaining student achievement, persistence, and interest.