The author makes the case for designing physics instruction so that all students can succeed.
by Stewart E Brekke, MS in Ed, MA
Regular contributor to the Gazette
July 1, 2009
If properly taught, high school physics is accessible to all students, average and above, the 50% above the mean, not only the upper 20%. By high school physics, I mean a course involving a substantial amount of algebra, some trigonometry, and problem solving. In order to make a course such as this successful for the many, not only the few, some changes must be made in the course format.
First, students must be given help with problem solving. Marginal physics students became successful if given substantial amounts of immediate feedback and provided with more than one instructor in the room as well as a prepared workbook to provide students with needed on the spot help. Success has also been reported in required high school physics by giving substantial help with problem solving in Chicago inner-city high school students by the use of drill and practice with algebra and trigonometry. Calculators may be used to breach the persistent problem of arithmetic deficits in fractions and decimals, as well as in division of numbers.
Second, for a high school class required for all students or a general high school physics course, there must be relatively direct instruction. Instruction should generally proceed from the concrete to the abstract, not the other way around. Physics teachers should remember that most students do not have much experience with physics problem solving or concepts and that adolescents learn when subject matter is tangible or concrete. For example, one physics teacher pleaded for structure when the PSSC was instituted in the 60s and threw even high level high school physics classes into chaos. He advocated less emphasis on thinking and more on skills. As he put it, “skills before theory, please!” Teachers should also remember that there is a difference between inquiry and scientific inquiry and that a solid knowledge base is required for any kind of meaningful thinking.
Third, adolescents like all humans, become good at what they do through drill and practice. The more students do a task, the better they become at it. Many high school physics texts ignore this basic principle of learning and give only one problem of each type, so that problem types are not readily learned and foundation for solving more advanced problem types is weak as a result of a poor knowledge base. Many texts in physics, from high school to graduate, ignore this basic law of learning that practice makes perfect.
Also, many of the problems in the high school physics texts are not modeled. Problems are often given for which there is not example on how to solve them in the text. For students with virtually no background in the specifics of the problem, this is tantamount to never having the problem solved.
Young students need many examples in the text or else they will not be able to get solutions unless they have a close relative or neighbor to help them. No matter how much thinking or time the average high school student puts in on a problem, they will never solve it unless an example is given in some form. According to educational research, it is the solving of the problem that leads to the confirmation one’s skill, a pleasurable consequence, not the struggling with it. Pleasurable consequences lead to positive reinforcement and learning. With success, students become more apt to stay in the field and physics enrollments thereby increase. As long as the high school physics texts ignore the basic facts that practice makes perfect, and that pleasurable consequences produce learning, physics instruction will suffer and enrollments will stay low.
Many texts, not only high school physics texts, commit the error of “mentioning.” In “mentioning,” the text refers to a concept in a few sentences or words and these words are not set apart from the rest of the text. The student is then expected to know these few words as the important part of a question or test at the end of the chapter. Physics texts often state principle verbally and then expect the student, usually a novice, to solve a problem using a formula not even printed in the text. Often, instructors in high school and college physics cannot solve these problems either and, unknown to the student, have a problem solver or solution manual that accompanies the text hidden away in their offices where they learn to solve the problems in the text with ease.
Many at-risk students, I have found, do not learn from examples in the book or from examples on the board. They learn from the teacher going around the room showing them how to do a particular problem and then practicing on two or three more of the same type so that they get the idea of how to do a particular physics problem. As time goes on, the students usually become more independent in their problem solving and laboratory work. With this extra help, the many at-risk and less motivated students become good physics problem solvers and potential physics majors.
Many university physics researchers and teachers would be surprised at the variety and kind of high school students capable of doing the standard problem solving mathematical course. With success in problem solving using calculators, all of the students become interested in the course and look forward to coming to the course each day. Also, we provide all the students with a true understanding of physics and the capacity to go on in the sciences as well as enhancing their rationality and organized thinking.
I have found that all students can do basic modeling of laboratory data using simple models of curves and their formulas such as lines, parabolas and hyperbolas. They identify the basic equation for the curve such as y = kx, y = k/x or y = kxB2 after plotting the data if they use an approximate best-fit approach. With repeated help at the beginning of the course, most students can find the approximate formula of any phenomena they take data on. Again, the scientific or simple arithmetic calculator has helped enormously in the calculation of various quantities in the laboratory situation such as calculating the approximate height of the school building using the stopwatch to time the descent of a rock. The calculator has made the doing of physics, problem solving and labs, much easier for all students, and allows them to concentrate on the phenomena under study rather than on tedious calculations by hand. This is especially true for at-risk type students.
To make the high school introductory course appeal to most students they must be assured of success if they make an effort. Therefore, other criteria besides problem solving must be used for grading students. I think that problem solving on tests should be the main criterion for grading provided lots of help is given in solving practice problems. Most students, from those interested in band to zoology, can solve basic physics problems if given lots of help especially at the beginning of the course. However, reports, library research, and even artwork and extra credit for science fairs may help students pass the course. In addition, giving points for contributions in those activities can sometimes offset weakness in math skills. One student who was unable to count worked so hard on reports and in the lab that he received a good grade even though problem solving tests constituted 50% of the course grade.
Therefore, to improve high school physics teaching and enrollments, efforts must be made to:
Give lots of problem solving help
Improve high school texts to conform to the principles of learning established in educational psychology research
Design a course so all can succeed in some way through non-mathematical means.
Physics does not have to be a non-mathematical course. This sells out the student, depriving them of the true nature of the subject, and thereby deluding them. What high school physics needs is better problem solving help and a more concrete approach to reach all students.