Physics lab courses are an essential part of the physics undergraduate
curriculum. Learning goals for these classes often include the ability to
interpret measurements and uncertainties. The Physics Measurement Questionnaire
(PMQ) is an established open-response survey that probes students'
understanding of measurement uncertainty along three dimensions: data
collection, data analysis, and data comparison. It classifies students'
reasoning into point-like and set-like paradigms, with the set-like paradigm
more aligned with expert reasoning. In the context of a course transformation
effort at the University of Colorado Boulder, we examine over 500 student
responses to the PMQ both before and after instruction in the pre-transformed
course. We describe changes in students' overall reasoning, measured by
aggregating four probes of the PMQ. In particular, we observe large shifts
towards set-like reasoning by the end of the course