Scaffolding to Improve Reasoning Skills in Problem Formulation Abstract Educators in engineering and science disciplines are well aware of student difficulties in formulating problems. Correct problem formulation is a critical phase in the problem solving process because the solution follows directly from the formulation. Students in this phase are engaged in reasoning and argumentation activities that result in support for a specific formulation. Empirical evidence from our work in ill-structured STEM problem solving indicate that more research is needed to understand the nature of problem formulation and what the cognitive challenges are for STEM students. Students work in teams to solve ill structured problems in the Problem Solving Learning Portal (PSLP). In this study we examine the use of scaffolding in the problem formulation stage in the context of an Engineering Economy course having students from multiple engineering disciplines.