Research: Iterative Decision-Making Improves Critical Thinking

• By Dian Schaffhauser
• 08/26/15

Want to help your students improve their critical thinking? Then give them opportunities to make decisions during your lab exercises. According to a research project at Stanford University and the University of British Columbia, students who make decisions about how to improve their data gathering abilities, even in the simplest of experiments, gain skills of decision-making that will help them in more advanced science courses.

The research team that undertook this study followed first-year students attending an introductory physics lab course at the Canadian university. To establish a baseline, they monitored what students were and weren't learning when instruction followed conventional practices for performing lab experiments.

For one such experiment, students swung a pendulum and used a stopwatch to time the duration between the two angles of amplitude. They collected the data, compared it to what was in the textbook, noted what didn't match and moved on.

Then the researchers modified the course. Students were asked to make decisions about how they could improve the quality of their data collection and explain the differences between their results and what the textbook said.

Among the improvements, students added to the number of trials they performed to gather more data; they marked the floor for greater precision in swinging the pendulum and measuring the angles; they tested out changes in how the timer was operated.

Those tiny decisions improved their understanding of the processes at work and bolstered their confidence in performing science.

"By actually taking good data, they can reveal that there's this approximation in the equation that they learn in the text book, and they learn new physics by this process," said Natasha Holmes, the lead author on the study. Holmes began on the research as a doctoral candidate at U British Columbia. Now she's building on the project as a postdoctoral research fellow at Stanford. "By iterating, making changes and learning about experimental design in a more deliberate way, they come out with a richer experience," she noted.

The research team found that those students who tweaked their decision-making approaches were 12 times more likely to think of and test out ways to improve their data gathering than students following the traditional instructional approach. Also, the test students were four times more likely to identify and explain the limits of their predictive model based on their data.

A year later, these same students were still applying similar critical thinking skills in another physics course.

"This is sort of a radical way to think about teaching, having students practice the thinking skills you want them to develop; but in another way it's obvious common sense," said co-author Carl Wieman, a professor of physics and of education at Stanford. "Students leave this class with fundamentally different ideas about interpretation of data and testing against model predictions, whether it's about climate change or vaccine safety or swinging pendulums."

Now Holmes is testing out the lessons learned from the research in other kinds of undergraduate courses. "Students tell me that it helped them learn what it means to do science, and helped to see themselves as scientists and critical thinkers," she said. "I think it's done a whole lot for their motivation and attitudes and beliefs about what they're capable of. So at least from that perspective, I think experiment design that encourages iterative thinking will have huge benefits for students in the long run."

The findings of the research were recently published in the Proceedings of the National Academy of Sciences.