A new unit of measurement for introductory physics lab

Abstract

In introductory physics labs, a challenge arises when students are asked to measure a well-known quantity, such as the free fall acceleration, g. Students often don't perform a proper error analysis if they already know the correct answer, and their result is “close enough.” Masking, or disguising the correct answer, as is often done in nuclear and particle physics research, encourages students to be more careful. In this paper, we introduce a new unit of measurement; in these units, students don't know what the value of g should be, leading to a more engaging and authentic scientific experience. Additionally, we instituted a mock “conference” in which students settled on a consensus value of g in this new system of units. When students quantitatively compare their measurements of an unknown quantity, it motivates them to perform a detailed error analysis. Student feedback on this reformed lab was largely positive.