A study on teaching critical thinking in science
Teaching the scientific method yields large learning gains but not as a standalone unit
Column by JILL BARSHAY
January 13, 2020
In September 2019, I wrote about a review of the research on how to teach critical thinking by University of Virginia professor Daniel Willingham. His conclusion was that generic critical thinking skills don’t translate from one subject to another but that subject-specific critical thinking skills can be explicitly taught as you go deep into a lesson, be it history or math, as students need to learn a lot of information to process it.
A large study on teaching science to middle school students was published afterwards and it adds more nuance to this debate between critical thinking skills and content knowledge. A team of researchers found that students who learn to think like a scientist learn many more of the facts and figures in their science classes and absorb the content better.
The big wrinkle is that the researchers found that it’s not effective to start the school year with a couple of weeks of lessons on the scientific method, which many teachers do. Instead, the successful teaching of scientific thinking starts with a content-rich lesson where students learn to ask the right questions and evaluate evidence while they are processing information on dolphins, molecules or another specific science topic.
In other words, critical thinking is necessary to absorb content better but a content-rich lesson is needed to teach critical thinking in the first place.
The study, “Scientific sensemaking supports science content learning across disciplines and instructional contexts,” was published in October 2019 in the journal of Contemporary Educational Psychology. The researchers were Matthew Cannady at the University of California at Berkeley, Joo Man Chung from Georgetown University and Christian Schunn and Paulette Vincent-Ruz, both from the University of Pittsburgh.
In the study, researchers tested more than 2,500 sixth and eighth grade students multiple times during fall term, measuring their scientific reasoning abilities separately from how much content knowledge they were learning in biology or chemistry classes. The students hailed from a large Eastern city with a high proportion of black students and from several school districts in the West where there were many Latino students.
The researchers measured “thinking like a scientist” by breaking down the thinking and analyzing that scientists do into categories, such as asking questions, designing experiments, interpreting data, constructing cause-and-effect explanations, making arguments and understanding how scientific theories evolve. Much of it involves the skills you would need in order to follow the scientific method of generating, testing and modifying hypotheses. For example, the researchers were interested in how students were able to connect claims to evidence, prioritize which forms of justification to use as evidence and refute alternative claims. The adjacent table from the study provides concrete examples of how students were assessed.
A breakdown of thinking like a scientist
On the left are the researchers’ categories of thinking scientifically. They largely adhere to aspects of the scientific method. On the right are examples of questions that the researchers used to gauge whether middle school students grasped how to think scientifically. Click here to see a larger version of this table. Table 2 from "Scientific sensemaking supports science content learning across disciplines and instructional contexts" by Matthew A. Cannady, Paulette Vincent-Ruz, Joo Man Chung and Christian D. Schunn, published October 2019 in the journal of Contemporary Educational Psychology
The researchers calculated that students who started the year with a higher degree of scientific reasoning learned considerably more content during the term than students who didn’t have as strong a sense of scientific reasoning. It was true in both biology and chemistry classes and for both sixth and eighth graders.
The researchers also paid close attention to the style of instruction in the science classrooms. Some teachers adhered closely to a textbook. Others had a more hands-on approach with lots of experiments and projects. Hands-on instruction tended to produce more growth in scientific reasoning for students; doing science is helpful for learning to think like a scientist. However, one surprising result is that the researchers didn’t see a difference in the amount of content that a student learned between the two teaching approaches.
Both styles could be done well, helping students to learn how to reason like a scientist, and both could be done poorly. For example, a hands-on teacher can merely ask students to follow step-by-step instructions in a prepackaged experiment kit without pushing students to think through why they’re doing these steps. Meanwhile, a textbook teacher can ask fabulous questions.
Those questions seem to matter the most. For example: Why did you ask that question? Why is it a good or reasonable question? Why is the study you designed the right study to answer that question? Why does the data support your idea?
Why strong scientific reasoning helps you learn more facts and figures is mysterious. Learning scientists have a couple of theories. One has to do with information processing. The human brain is constantly mishearing and misreading things. If we understand what should be going on and are trying to make sense of the information coming to us, we fix the errors.
The other theory is based on how human memory works. When we try to understand new information and make connections between ideas, learning scientists say it takes less effort to memorize new facts and figures. Another approach is repetition. And certainly studying something 10 times is more effective than only five times. But understanding it once is better.
When I first became an education reporter almost a decade ago, I remember education policymakers and experts explaining to me that we don’t need to teach students as much boring content anymore because you can look up everything you need to know on Google. They believed that thinking skills are the really important thing to teach students and that’s what will last with students year after year after they’ve forgotten all about the periodic table. But this research shows that you can’t learn how to think as an abstract skill. You have to dig into the “boring” and “forgettable” content to acquire it.
This story about teaching the scientific method was written by Jill Barshay and produced by The Hechinger Report, a nonprofit, independent news organization focused on inequality and innovation in education.