articlePhysics

Please Note: This is a draft version of the article that appeared in National Association of Laboratory Schools Journal, Vol. XXII, No.1, Winter 1997-1998. Please refer to the published version if quoting.

Alternatives to Traditional Physics Instruction: Student Perceptions of the Effectiveness of a Conceptual Physics Approach

T. Griffith Jones
Science Department Chair

P. K. Yonge Developmental Research School

University of Florida

Linda Cronin Jones
Associate Professor of Science and Environmental Education

Department of Instruction and Curriculum

University of Florida

Tracey Zander
Graduate Student

Department of Instruction and Curriculum

University of Florida

Introduction
It's no secret that physics is the least popular science course offered in U.S. high schools. It's also no secret that students (and many teachers) perceive physics as the most abstract, irrelevant, and confusing science course in the high school curriculum (Franz, 1983). Numerous questionnaires and surveys have been administered to determine why so few high school students choose to enroll in physics and the results are consistently similar: most high school students feel physics contains too many facts/technical terms to learn, requires too much of a math background, and the textbooks are too difficult to read (Ogunsola-Bandele, 1996). Most high school (and college) students avoid physics because of its reputation as an applied mathematics course (Toews, 1988). This has resulted in decreased enrollments in physics at a time when our society desperately needs scientifically literate citizens. Just mentioning the word physics seems to make students cringe and elicits responses like: "Ooh, that is hard stuff." or "I can't understand physics because I'm not good in math." Even most adults react with sour expressions and responses such as: "I never liked that class when I was in school, too much math." or "Physics was so complicated, I was always lost in that class." In fact, we used to respond that way ourselves as high school and college students. Then, about eight years ago, we received a complimentary copy of a high school Physics text authored by Paul G. Hewitt called, appropriately enough, Conceptual Physics. What struck us most about this unusual text was the fact that it focused almost exclusively on the ideas of physics and included virtually no math beyond some basic algebra and formulas. In addition, it was chock full of real world examples illustrated with lively and entertaining cartoons. Reviewing the book, we all commented that we wish we could have had such a text when we were taking physics.

We began trying to find out if other high schools had successfully tried replacing their traditional math-based physics program with a conceptual one. We were only able to find information about one study conducted in 1985 at Ball State University's Burris Laboratory School (also a K-12 school) in Muncie, Indiana (Hewitt, 1990). In this study, Nancy Watson began teaching physics conceptually to eighth graders in physical science classes. She reported both an increase in enthusiasm and enrollment. She credited the conceptual foundation developed in middle school for the 30-50% increase in subsequent physics enrollment at her high school. It seemed like the time was right to try the conceptual approach at the high school level.

The Text

The Conceptual Physics text was designed specifically for introductory-level high school physics students. The text is extremely readable, with a Fry readability level of 8th grade, and is accompanied by a complete set of supplementary resource materials, including an excellent lab manual. The author promotes a "concepts before computations" approach (Hewitt, 1994). He stresses the need to have students first understand the concepts before attempting intimidating algebraic manipulations and computations. Mathematics is part of the program but it is not it's foundation. Instead of being the main focus of physics, in this program math is treated as a tool that can be used to help develop and express key physics concepts.

Instructional Approach

When designing our lab school's new conceptually-based physics course, we decided to apply the educational philosophy of the Learning Cycle, first developed by Atkins and Karplus in 1962. The Learning Cycle is a three-stage instructional approach with a sequence of lessons designed to first engage students in exploratory investigations, then promote conceptual development of their new discoveries, and finally allow students to apply their new knowledge in novel contexts (Karplus, 1972). The Learning Cycle approach is consistent with current constructivist theory, advocating the idea that students learn best when they are allowed to construct their own understanding of concepts over time by active engagement in the learning process (Roth, 1994).

In our school's conceptual physics program, the first or Exploration stage consists of engaging students with discrepant events, demonstrations, lab activities or thought-provoking questions. These techniques capture the students' interest, as well as provide instructors with insights regarding initial student conceptions (or misconceptions). Experiences in this phase also help clue students in to the focus of upcoming lessons.

In the second or Concept Development stage, textbook reading assignments, lectures, demonstrations, lab activities, computer simulations, videos, laser videodiscs, and/or class discussions are used to explain the observations and experiences of students during stage one. During this stage, key vocabulary terms and math equations are introduced as tools to guide student thinking rather that as facts or formulas to be memorized.

In the third or Application stage, students further explore the newly developed concept with hands-on experiences, word problems, or textbook-integrated computer simulations requiring them to use the terms and formulas presented in stage two to solve new problems and apply the target concept to new situations. The application of the concepts via technology is an effective method to reinforce student conceptual understanding of physics concepts as well as a means to make learning physics less abstract and more relevant for all students (Escalada et al., 1997).

With this approach, computational problem solving is introduced only after students have demonstrated a solid understanding of the underlying concept. Since algebraic manipulations and computations are found within many of our state's objectives for Physics I, they must be covered; but too often their coverage becomes the driving force of the course. In our program, physics is not treated as an applied mathematics course. Instead, math is seen as a symbolic language that can be used to interpret, express, and apply physics principles.

The Survey

With these changes to our physics program, we intended to make physics less elitist and more accessible to all 300+ students in our high school. In the seven years we have been teaching physics with a conceptual approach, enrollment has increased from 10 to 65 students per year with more than 45% of our graduates completing physics. Minority enrollment has jumped from 0% up to 34%; enrollment of African-American females has improved from 0% up to 14%; and overall female enrollment in physics has been as high as 61%. We believed part of our success with female and minority students was due to the fact that our conceptual approach de-mystified physics and challenged stereotypical views that physics is only for future college science majors. To document this belief, and find out more about our students' perceptions regarding the effectiveness of the conceptual physics approach, we conducted a more formal survey.

Our survey questions focused on former physics students' perceptions of the effectiveness of the Conceptual Physics text and our learning cycle-based instructional approach. The instrument we used addressed the same three curricular areas usually included in textbook selection committee instruments, i.e. content (11 items) , presentation (9 items) , and instructional design (4 items). Additionally, our survey addressed student perceptions regarding their preparedness for college-level physics courses (2 items) and the impact of the conceptual physics program on their attitudes towards physics and science in general (5 items).

A Likert-type response scale, with options ranging from 5 (Strongly Agree) to 1 (Strongly Disagree) was used. We also invited respondents to include additional written comments if they wanted to.

Study Sample

We administered student surveys in two phases. In the first phase, we mailed the instrument to 59 P. K. Yonge graduates who had completed Physics as juniors or seniors in the 1991/92, 1992/93, 1993/94 or 1994/95 school years. Twenty-five percent of these former students responded. In the second phase, we administered the survey to 17 seniors at P.K. Yonge during their homeroom period in the Spring of 1996. These students had completed the physics class as juniors in 1994/95. To control for variations in responses due to different physics instructors, all of the students selected for this survey had had the same physics instructor and used the same edition of the Conceptual Physics text. A summary of sample demographics is included in Table 1.

Table 1. Respondent Demographics

GENDER NUMBER OF STUDENTS

Female .............................................................17

Male ................................................................15

TOTAL ..............................................................32

ETHNIC GROUP NUMBER OF STUDENTS
Asian ............................................................... 2

East Asian Indian ................................................. 1

Hispanic ........................................................... 3

Black ............................................................... 5

White ............................................................... 21

TOTAL .............................................................. 32

Survey Results

Content Items

Survey results indicate that students completing our conceptual physics program felt the content of the textbook was thorough and relevant. Students felt strongly positive about the scientific accuracy and timeliness of the course content and considered the concepts covered important for effective functioning in work and leisure. They also felt the conceptual physics program fostered critical thinking and problem solving and real-life applications. Areas which could be improved include providing more information about safety hazards and precautions, more integration of physics concepts with social, multicultural and environmental issues, and more emphasis on career opportunities related to physics.

Survey Response