Background: As engineers solve problems that are ill-structured and require collaboration, a common goal of engineering programs is to develop students' competencies for solving such problems in teams, often using cornerstone design experiences. Purpose: With the goal of designing effective learning environments, this study identifies qualitatively different ways that engineering students experienced ill-structured problems while working in teams. Design/Method: This phenomenographic study employs interview data from 27 first-year engineering students. Iterative data analysis resulted in categories of student experiences and their logical relationships. Results: Seven categories describing collaborative, ill-structured problem-solving experiences emerged: completion, transition, iteration, organization, collaboration, reasoning, and growth. These categories are organized in an outcome space along dimensions we call reaction to ambiguity and use of multiple perspectives that can be used to frame students' perspectives from less comprehensive to more comprehensive. Conclusions: First-year engineering students experience team-based, ill-structured problem solving in a variety of ways. The resulting outcome space is of practical use to educators who teach courses involving collaborative, ill-structured problem solving.