  Measurement uncertainty is a critical feature of experimental research in the
physical sciences, and the concepts and practices surrounding measurement
uncertainty are important components of physics lab courses. However, there has
not been a broadly applicable, research-based assessment tool that allows
physics instructors to easily measure students' knowledge of measurement
uncertainty concepts and practices. To address this need, we employed
Evidence-Centered Design to create the Survey of Physics Reasoning on
Uncertainty Concepts in Experiments (SPRUCE). SPRUCE is a pre-post assessment
instrument intended for use in introductory (first- and second-year) physics
lab courses to help instructors and researchers identify student strengths and
challenges with measurement uncertainty. In this paper, we discuss the
development of SPRUCE's assessment items guided by Evidence-Centered Design,
focusing on how instructors' and researchers' assessment priorities were
incorporated into the assessment items and how students' reasoning from pilot
testing informed decisions around item answer options. We also present an
example of some of the feedback an instructor would receive after implementing
SPRUCE in a pre-post fashion, along with a brief discussion of how that
feedback could be interpreted and acted upon.
