Authors: Cole Walsh, H. J. Lewandowski, N.G. Holmes
First author’s institution: Cornell University
Journal: Physical Review Physics Education Research, 18, 010128 (2022)
Throughout my time as a physics student, I’ve encountered various types of lab-courses. Some were focused on verification where the instructor asked me to follow a given procedure to confirm some known result such as the value of acceleration due to gravity on Earth. Other times, the instructor provided a general problem and asked me to solve it, requiring me to learn experimental design and data analysis skills along the way.
My experience wasn’t atypical of what physics students often encounter. Prior work has found a wide range of goals instructors have for their physics courses, including demonstrating or reinforcing known theories and laboratory skill development. As a result of the wide variation in the goals of physics labs, there is limited evidence about the efficacy of labs. For example, prior work has found that for labs with the goal of reinforcing concepts, there is limited impact (we’ve covered one of those studies in a previous post). In addition, these type of labs have been found to cause students to have more negative attitudes and beliefs about experimental physics by the end of the course than they had at the beginning!
These results are not inevitable, however. Labs designed to develop skills have been found to show the opposite effect regarding attitudes and beliefs (though still showed limited success regarding conceptual knowledge). The goal of today’s paper is to better understand how labs affect students’ views about experimentation and how different types of lab courses impact students’ critical thinking skills.
For their study, the authors used data from the Colorado Learning Attitudes about Science Survey for Experimental Physics (E-CLASS) and the Physics Lab Inventory of Critical Thinking (PLIC) from over 20,000 students across 100 different institutions. These two surveys are given in a pre/post course format and allowed the researchers to understand how students’ views of experimental physics and their critical thinking skills changed as a result of the laboratory course.
In addition, the researchers also collected information about the lab course from an instructor survey. Through this survey, the researchers were able to determine what the goals of the lab were as well as key information about the course.
The researchers then used mixed model linear regression and confirmatory factor analysis to analyze their data. When analyzing their data, they viewed the results through a lens of equity of individuality where the goal is to improve outcomes of marginalized students as opposed to focusing on closing gaps between marginalized students and non-marginalized students. Under this framing, the central question is whether labs with different purposes provide benefits to all students as opposed to the differences between groups.
When looking at their results, the researchers found that students in labs where developing skills was the focus (skills-based lab courses) scored 0.2 standard deviations higher on both the E-CLASS and PLIC than students in labs where understanding concepts was the focus (concept-based lab courses). This was true even after controlling for pre-course responses and demographics. Courses that had goals that included both developing skills and concepts had gains better than the concept-based lab courses but worse than the skills-based lab courses. These results suggested skill-based labs were more effective in making students’ views about experimental physics more positive and developing their critical thinking skills than concept-based lab courses were. In addition, all students seemed to benefit in the skill-based lab courses, though students of some backgrounds saw more of a benefit than others.
To understand why this might be, the researchers then looked at the instructor surveys. They found skills-based labs engaged students in more decision making and communication tasks than concept-based lab courses did (again, labs that had both goals were in the middle). Interestingly, the amount of modeling (e.g. developing an explanation or model for why a phenomenon occurred) in the lab was similar in all of the labs, regardless of whether the goals of the lab were concept-based, skill-based, or a mixture of the two.
The researchers then looked at whether there were any associations between the three types of activities in the lab courses (modeling, communication, and decision making). They found that engaging in modeling was moderately correlated with decision making and communication tasks but that engaging in decision making tasks and communication tasks were highly correlated.
Finally, the researchers looked at how the use of these three types of activities in lab courses might explain the differences in E-CLASS and PLIC scores between skill-based and concept-based labs. They found that less than 10% of the increase in scores could be attributed to the modeling activities in the lab course but that 34-41% of the score increase on the E-CLASS could be attributed to decision making and communication opportunites (58-76% for PLIC, respectively).
Overall, the results suggest the skill-based labs appear to be more effective in developing students’ mindsets around experimental physics and critical thinking skills compared to concept-based labs. The researchers found that these gains were attributable to more decision making and communication opportunities in the skill-based labs than in the concept-based labs. Interestingly, the amount of modeling opportunities in the course did not matter, likely because both skill-based and concept-based labs had similar amounts of modeling opportunities. It is important to note however, that the amount of opportunities was based on the instructor’s perceptions of what happened in the course rather than what necessarily happened.
Going forward, the authors encouraged additional work about how various types of labs affect student learning and their experiences in the course. For example, because skills-based labs improved attitudes around experimental physics and that students with expert-like attitudes are more likely to persist in physics, a greater use of skills-based labs might help retain students in physics. However, additional work is needed to know if that is true.
Header image by Photosynthesizer via Pixabay
I am a postdoc in education data science at the University of Michigan and the founder of PERbites. I’m interested in applying data science techniques to analyze educational datasets and improve higher education for all students