  In a recent report, the American Association of Physics Teachers has
developed an updated set of recommendations for curriculum of undergraduate
physics labs.1 This document focuses on six major themes: constructing
knowledge, modeling, designing experiments, developing technical and practical
laboratory skills, analyzing and visualizing data, and communicating physics.
These themes all tie together as a set of practical skills in scientific
measurement, analysis, and experimentation. In addition to teaching students
how to use these skills, it is important for students to know when to use them
so that they can use them autonomously. This requires, especially in the case
of analytical skills, high-levels of inquiry behaviours to reflect on data and
iterate measurements, which students rarely do in lab experiments. In this
paper, we describe a simple framework for structuring the critical thinking and
inquiry behaviours relevant to lab work, which focuses on iterative cycles of
comparisons between data sets. We describe the framework and demonstrate
examples of its use in an introductory physics lab course.
