- Aaron Johnson's research focuses on how mathematical models are taught in undergraduate engineering science courses and how these models are used in analysis and design. Homework and exams often ask students to apply mathematical models to well-defined problems for which there is a single correct answer. However, professional engineers deal with ill-defined, complex problems in which the core engineering practice is not the calculation of the answer but the modeling of the problem. The modeling abilities of engineers are the quality of engineering judgment, and Johnson's research seeks to understand how undergraduate engineering students can productively engage in the beginnings of engineering judgment. He also develops assignments and technology tools to engage students in these productive beginnings.