2022 First-Year Engineering Experience

GIFTS: Assumptions, Approximations, and Dimensional Analyses, Oh My!

Presented at Technical Session T2

It is critical that first-year engineering students understand the value of and the process required for solving open-ended problems. The content and context for our Introduction to Civil Engineering course is built around a famous quote from a well-known structural engineer, Sir Ove Arup. He stated that: “Engineering problems are under-defined; there are many solutions, good, bad and indifferent. The art is to arrive at a good solution. This is a creative activity, involving imagination, intuition and deliberate choice.” In this course, we challenge students to construct and document potential solutions for under-defined problems that do not have a singular right answer. We use a structured approach for problem-based learning that is collaborative and supportive. The GIFT focuses on the first step in that structured approach.

To start the open-ended solution process one must make a reasonable first estimate. Making estimates is much different from the closed-form solutions that most students are comfortable with. Choices must be made, often with limited information and knowledge. We demonstrate that with finding answers to Fermi questions. Students learn how to make assumptions and approximations while understanding how to differentiate one from the other. Assumptions and approximations are often correlated and students practice making those connections. The process of making approximations reinforces the importance of being careful and intentional about selecting units of measure. A numerical answer to the Fermi question is then calculated by setting up and performing a series of dimensional analyses, most commonly in the form of unit conversions. The GIFT will further define these three components and describe how we guide students to use them in making first estimates for open-ended problems.

  1. Dr. Charles E. Pierce University of South Carolina [biography]
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