Skills-focused lab instruction improves critical thinking skills and experimentation views for all students

Instructional labs are fundamental to an undergraduate physics curriculum, but their possible learning goals are vast with limited evidence to support any particular goal. In this study, we evaluate the efficacy of labs with different goals and structures on students’ critical thinking skills and views about experimentation, using an extensive database of survey responses from over 20 000 students at over 100 institutions. Here, we show that labs focused on developing experimentation skills improve students’ critical thinking skills and experimentation views compared to labs focused on reinforcing lecture concepts. We further demonstrate the positive impacts of skills-based labs over concepts-based labs on these outcomes across students’ gender and race or ethnicity. Our analysis also shows that activities to support students’ decision making and communication explain over one-half and one-third of the effect of skills-based labs on students’ critical thinking skills and experimentation views, respectively, while modeling activities have only a small effect on performance.

Figure 1

Expected post-test scores (i.e., marginal effects) across lab type and student demographics. Pretest score is fixed at the mean, while all other variables are fixed at their proportions. Students score higher at post-test when enrolled in skills-based labs as compared to concepts-based or mixed labs and the pattern is consistent across student demographics (when precision can distinguish the groups). Error bars represent one standard error (68% confidence interval). We have not shown marginal effects on the PLIC for students who identified as nonbinary, an unknown gender, American Indian or Alaska Native, or Native Hawaiian or Pacific Islander due to error bars that exceed the range of the plots. These students were included in our models, however, and full results can be found in Appendix pp3.

Figure 2

Density plots of the amount of agency, modeling, and communication in labs with different intended purposes.

Figure 3

Expected post-test scores (i.e., marginal effects) on the E-CLASS and PLIC as a function of time spent on decision-making, modeling, and communication activities. Post-test scores are higher in labs with more activities related to decision making and communication, with a small effect from modeling activities. The shading represents the 68% confidence intervals on the estimates.

Figure 4

Model diagnostic plots for the linear mixed models. There is no noticeable trend in the residuals for either model. There are generally departures from normality in the residuals at the tails of the distribution, however, which is not uncommon and does not generally affect the interpretation of $p$ values [67].