It seems obvious that teachers need to understand the content they're trying to convey to students. But a new study finds that what's especially critical to improved science learning is that teachers also know the common misconceptions students have. And in science, there are plenty of things that young peopleand a lot of adultsdon't correctly understand, such as what causes the change of seasons.
The study, conducted by researchers at the Harvard-Smithsonian Center for Astrophysics, targeted middle school physical science. The researchers enlisted 181 teachers to administer a multiple-choice test of student knowledge of science concepts. Twelve of the 20 items were designed to have a "particularly wrong answer corresponding to a commonly held misconception," explained Philip Sadler, the lead author and a senior lecturer at the Harvard-Smithsonian center.
The "unusual" part of the study, he said, was that teachers also took the test, and were asked to identify both the correct answer and the one students were most often likely to incorrectly select. Although the teachers overall did "quite well" at selecting the correct answer, the results were more mixed in predicting students' incorrect response.
"Teacher knowledge was predictive of higher student gains. No surprise there," Sadler explained in an email. "However, for more difficult concepts where many students had a misconception, only teachers who knew the science and the common misconceptions have large student gains." What's key, he said, is knowing "what was going on in their students' heads."
The study, supported by funding from the National Science Foundation, was recently published online in the American Educational Research Journal. The study also is the focus of an article published yesterday in Science Daily.
The researchers acknowledge that many educators question the value of tests composed of multiple-choice items, but said in the study that when items are written to include popular misconceptions as "distractors, they function well in diagnosing misconceptions that impede the learning of science." The test questions were based on concepts covered in a set of science content standards published by the National Research Council in 1996. Topics addressed included properties of matter, motions and forces, and transfer of energy.
In his email, Sadler said the study was sparked by the reaction many educators have had to a video he helped to develop, called "A Private Universe," in which graduating Harvard University seniors reveal "the same wrong ideas" about science as middle-school students.
"So many teachers have sought me out at conferences after viewing [the video] to tell me that it was a turning point in their teaching of science," he said. "They report that although they knew that some students had unusual ideas, they were unaware of the extent and near universality of misconceptions concerning concepts that they teach."
By the way, while I had Sadler's attention, I asked him for a few quick thoughts about the Next Generation Science Standards just finalized. He was upbeat about the standards, but cautioned that effective implementation will be a heavy lift.
"I think they represent a terrific ideal for what students should be learning," he said. "However, their implementation really depends on investing in teacher professional development, more lab equipment, and far better assessments than we now have."