High School Physics Pain Produces Little Gain in College

High school physics, generally a prerequisite for college courses in the subject, does not provide much of a payoff once students encounter the realities of higher education. That's the conclusion of researchers who studied the effects of high school physics preparation on college physics performance. The study is the first to control for differences in socio-economic background, along with other variables. The study, which contradicts the conclusions of other, more limited examinations of the topic, was published in the May 1997 issue of The Physics Teacher. It was coauthored by Philip M. Sadler, assistant professor of education at the Harvard Graduate School of Education and director of the Science Education Department at the Harvard-Smithsonian Center for Astrophysics (CFA), and Robert H. Tai, doctoral candidate at HGSE.

"Our results challenge the wisdom of making high school physics a prerequisite for college physics," said Sadler. "That policy shuts kids out of future careers in medicine, engineering, or the sciences; yet it rests on some very shaky ground. Students with strong academic performance in high school or with a previous calculus course, perform equally well in college physics without having taken the subject in high school."

Nationally, almost 700,000 students take physics in high school each year, about 25% of all students. About 360,000 students take introductory physics in college, often as a requirement for engineering, science, or pre-med majors. Most high school teachers believe their physics courses are preparing students for college physics, perhaps, as Sadler discovered, because all previous studies showed that college students who studied physics in high school outperformed their classmates who did not. However, according to Sadler, these studies failed to control for demographic variables and all were undertaken at a single college or university.

In their study, Sadler and Tai included students from a wide variety of ethnic and socioeconomic backgrounds at 19 colleges and universities, including public and private institutions, and one national military academy. They surveyed the students about their preparation with a questionnaire administered during class time and student grades were later reported by the professor. Student success, measured by their college grades, was then used to measure the relationship between background and performance. Because professors graded their students using a variety of schemes, Sadler and Tai translated all grades to a comparable 100-point scale. When the researchers controlled for demographic variables (for example, wealthy suburbs offer more physics courses) and others, including overall academic achievement, high school physics contributed little more than one point. Other studies, using a similar measure but without controlling for variables, had found a six-point difference, or about half a letter grade.

The two researchers found that a student's high school grades in other courses and the level of mathematics taken in high school are much better predictors of college physics success. The problem for many students, they say, is a jam-packed high school curriculum.

"The strategy of a quick tour in high school through all the major areas covered by college physics courses bears little relation to future success," Sadler noted. "Our analysis of the teaching methods and curriculum suggests that a reduction in the number of topics covered and a corresponding increase in the depth of study of a few concepts leads to much higher grades in college physics courses."

Sadler and Tai also question the value of college faculty writing textbooks or designing high school courses that cover essentially the same material as introductory college courses. "Since most high school teachers feel that preparation for college physics is a major goal, they often use college texts or ones written by college professors," Sadler said. "However, we think time in high school might be better spent concentrating on a few key topics in physics, including relevant labs, computer software, and math, which genuinely prepare students for the rigors of college physics."