Fig. 1: AD plot of student responses on the reality cluster
Invited poster, presented at The International Conference on Undergraduate Physics Education (ICUPE), College Park, Maryland July 31-August 3, 1996. Proceedings to be published by the American Institute of Physics, E. Redish and J. Rigden, Eds.
Studies at the pre-college level by Carey[1], Linn[2], and others have demonstrated that students have misconceptions about science and about what they should be doing in a science class. When students' expectations are distorted by misconceptions about the nature of science, the nature of scientific knowledge, and the nature of what they can learn and how to learn it, what the students extract from the course may be very different from what the instructor expects.
Much of what we do in introductory classes does not address this hidden curriculum. Indeed, some of of what we do may be counterproductive. If we are to learn the extent to which it is possible to help introductory students transform their approach towards physics, we must observe our students carefully and try to explicate the elements of an appropriate set of expectations.
This paper reports on our observations of student attitudes and beliefs in introductory physics and how these attitudes and beliefs change as a result of physics instruction. In order to be able to probe these expectations in large classes, we have developed the Maryland Physics Expectations (MPEX) Survey, a Likert-style (agree-disagree) survey. In this paper, we display results on the distribution of student attitudes found by this survey and report on how these change as a result of physics instruction in a variety of instructional formats.
The success in finding ways to teach concepts is an excellent start (even though the successful methods are not yet widespread), but it does not solve all of our teaching problems with physics. We want our students to develop a robust knowledge structure -- a complex of mutually supporting skills and attitudes -- not just a patchwork of ideas, even if those ideas are correct. We want them to develop a strong understanding of what science is, how to do it, and how they themselves can do science. Is this something that we achieve automatically when we teach concepts successfully?
Despite extensive work on the importance of student expectations in many fields of study by workers in education, psychology, and cognitive science, very little work has been done on the college-level physics course. This course is of critical importance for scientists in many fields and is by now well documented to be unsuccessful for many students.[5]
One of the few studies of the role of student expectations in university physics was done by David Hammer.[6] He interviewed six students in the first semester of a university physics course at Berkeley for approximately 10 hours each. In these interviews, students were asked to solve carefully selected problems out loud. The interviews were taped and transcribed, and students were classified according to their statements and how they approached the problems.
Hammer proposed three dimensions along which to classify student beliefs about the nature of physics: beliefs about learning physics, beliefs about the content of physics knowledge, and beliefs about the structure of physics knowledge. In this paper, we describe two additional dimensions: beliefs about the connection between physics and reality and beliefs about the role of mathematics in learning physics. Table 1 lists these five dimensions and describes some of the contrasting beliefs assumed by students for each one.[7]
| Favorable Characteristics | Unfavorable Characteristics | |
|---|---|---|
| beliefs about learning physics: | takes responsibility for constructing own understanding | takes what is given by authorities (instructor, text) without evaluation |
| beliefs about the content of physics knowledge: | stresses understanding of the underlying ideas and concepts | focuses on memorizing and using formulas |
| beliefs about the structure of physics knowledge: | believes physics needs to be considered as a connected, consistent framework | believes physics can be treated as unrelated facts or pieces |
| beliefs about the connection of physics to reality: | believes ideas learned in physics are useful in accounting for phenomena in a wide variety of real contexts | believes ideas learned in physics are unrelated to experiences outside the classroom |
| beliefs about the role of mathematics in physics: | considers mathematics as a convenient way of representing physical phenomena | views the physical system and the mathematical formalism independently with no relationship between them |
The impact of instruction on these attitudes may be significant, but not necessarily positive. In an earlier study, Hammer carefully studied two students in the algebra-based physics course at Berkeley.[8] One student possessed many of the unfavorable characteristics, but was doing well in the course. The other student possessed many of the favorable characteristics, but was having trouble. Her desire to understand for herself more deeply was not supported by the course structure. She did not begin to succeed until she switched her approach to memorization and pattern matching. In this case the course encouraged an attitude and an approach to learning that most physics instructors would not endorse.
| Student Learning Dimension | Related Survey Item |
|---|---|
| beliefs about learning physics: | "Understanding" physics basically means being able to recall something you've read or been shown. |
| beliefs about the content of physics knowledge: | The most crucial thing in solving a physics problem is finding the right equation to use. |
| beliefs about the structure of physics knowledge: | A significant problem in this course will be being able to memorize all the information I need to know. |
| beliefs about the connection of physics to reality: | To understand physics, I expect to think about my personal experiences and relate them to the topic being analyzed |
| beliefs about the role of mathematics in physics: | All I learn from a derivation is that the formula obtained is valid and that it is OK to use it in problems. |
Despite some obvious limitations, we chose a survey as our primary data-collection instrument. Although repeated, detailed, taped and transcribed interviews with individual students are clearly the best way of finding out what a student really thinks, (in contrast to what they think they think) such interviews are both time consuming and expensive and cannot yield information about the distribution of student expectations in a large population. They are also unlikely to be repeated at many institutions. In order to survey a large number of classes and institutions, we created a survey which could be completed by a student in less than half an hour and analyzed by a computer. We refer to our survey as the Maryland Physics Expectations (MPEX) Survey.
Results presented in this paper reflect the current version of the survey. Only students who completed the survey both before and after the term were considered; we say that the data is matched. For this paper, we have combined the results for similar classes at a given institution. In order to highlight the development of student expectations from the onset, results reported here are from the first term of the introductory calculus-based physics sequence. As part of the process of validating our interpretation of student responses to the survey, we conducted student interviews. Either individually or in groups of two or three, students were asked to respond to the survey, describe their interpretations of the statements, and to indicate why they responded in the way that they did. In addition, students were asked to give specific examples from class that justify their responses.
From these interviews, we were able to determine when a survey item was interpreted in different ways by different students, or was interpreted in a way that was neither intended nor useful. For the items in which this was the case, we either changed the wording in an attempt to eliminate the difficulty, or we eliminated the item from consideration. The survey items included in this paper represent items where the interpretation by most students matched what was intended.
In order to test whether the survey correctly represent elements of the hidden curriculum, we tested the survey by giving it to a variety of "experts". Our baseline experts were a group of 22 physics instructors attending a Workshop Physics training session at Dickinson College in the summer of 1995 and 1996. These are faculty from a wide variety of institutions. Many have considerable experience in teaching, and all of them were sufficiently interested in educational development to have chosen to implement a highly interactive instructional model in their classes. When a student's response to a survey item is in agreement with the choice of most experts, we describe that response as favorable. If the response is not in agreement, we describe it as unfavorable.[9]
| Institution | Class Description (number of classes surveyed) | N (matched) |
|---|---|---|
| University of Maryland (College Park) | traditional (8) | 445 |
| Prince George's Community College | traditional (4) | 44 |
| Dickinson College | Workshop Physics (4) | 75 |
| Moorehead State University | Workshop Physics (1) | 12 |
| University of Minnesota | traditional (6) | 467 |
Due to space limitations, we will only discuss one of our dimensions in detail. Four survey items were constructed to attempt to reveal student beliefs about the connection between physics and reality. The statements presented to the students were the following.
Our results are displayed in Figure 1 as an agree-disagree (AD) plot. In this representation, we plot the percentage who answer favorably vs. the percentage who answer unfavorably. The percentages for the survey items included have been averaged. A data point in the upper left part of the graph corresponds to a class with largely favorable responses. Expert responses are in the upper left corner of the graph (by definition of favorable). The farther a data point is from the upper left, the greater the number of students who answered unfavorably. The distance of the data point from the diagonal line shown in the figure reflects the number of students who responded with "neutral" or who did not answer. Student pre-instruction responses are indicated with open symbols. The post-instruction results are indicated with closed symbols. The expert responses are indicated with a "+".
Fig. 1: AD plot of student responses on the reality cluster
Although not displayed in this paper, student responses along the other dimensions are also worthy of concern. For student beliefs about learning physics, many students apparently enter introductory physics believing that physics knowledge comes from an authoritative source and it is the responsibility of that authority to convey this knowledge to the student. Despite the fact that experts disapprove of this belief, our results suggest that traditional instruction does little to change this situation, and may even shift student views in the "wrong" direction. It is worth noting though that after completing Workshop Physics courses, many students do improve their views about learning physics.
For student beliefs about the content of physics knowledge, while students show some improvement after traditional instruction, none of the post results exceed 55% agreement with what our expert instructors would consider favorable characteristics. Finally, the other two dimensions show mixed results. For both student views about the structure of physics knowledge and student views about the role of mathematics in physics, student beliefs vary and the affect of instruction is questionable.
Fig. 2 displays the results averaged over all 31 items of the survey. We see that the average of student attitudes in introductory physics classes differs significantly from expert attitudes upon entry and that most classes surveyed lead to a deterioration of these attitudes rather than an improvement. In some cases this deterioration is substantial. We also note that in comparing differences between classes within a given institution with differences between institutions indicates that there are significant differences between the attitudes of incoming students at different institutions. This strongly suggests that care be used in transferring instructional approaches that are successful at one institution to a different type of institution.
Fig. 2: AD plot of total response of students on the MPEX Survey
[2] Linn, M. C., and Songer, N. B., "Cognitive and conceptual change in adolescence," Am. J. of Educ., 379-417 (August, 1991).
[3] For a review article, see McDermott, L.C., "What we teach and what is learned - Closing the gap," Am. J. Phys. 59, 301-315 (1991).
[4] For example, see Thornton, R. K., and Sokoloff, D. R., "Learning motion concepts using real-time microcomputer-based laboratory tools," Am. J. Phys. 58, 858-867 (1990); McDermott, L. C., Shaffer, P. S., and Somers, M. D., "Research as a guide for teaching introductory mechanics: An illustration in the context of the Atwoods's machine," Am. J. Phys. 62, 46-55 (1994); Shaffer, P. S., and McDermott, L. C., "Research as a guide for curriculum development: An example from introductory electricity. Part II: Design of an instructional strategy," Am. J. Phys. 60, 1003-1013 (1992); Redish, E. F., Saul, J. M., and Steinberg, R. N., "On the Effectiveness of Active-Engagement Microcomputer-Based Laboratories," to be published, Am. J. Phys. (1997).
[5] Hake, R. R., "Interactive-engagement vs. traditional methods: A six-thousand-student survey of mechanics test data for introductory physics courses", preprint; Tobias, S., They're Not Dumb, They're Different: Stalking the Second Tier (Research Corporation, Tucson AZ, 1990).
[6] Hammer, D., "Defying common sense: Epistemological beliefs in an introductory physics course," Ph.D. Thesis, U. of California, Berkeley, 1991; Hammer, D., "Epistemological beliefs in introductory physics," Cognition and Instruction 12, 151-183 (1994).
[7] Hammer also noted that students may state a belief in a favorable characteristic as a general character of the subject, but also state that the particular belief is not necessary for them to use in their own interaction with the physics course. See ref. 6.
[8] Hammer, D. "Two approaches to learning physics," The Physics Teacher 27, 664-670 (1989).
[9] For this part of the analysis the responses "agree" and "strongly agree" have been combined. Similarly, "disagree and "strongly disagree" responses have been combined. A netural response is considered neither favorable nor unfavorable.
[10] Redish, E. F., Saul, J. M., and Steinberg, R. N., in preparation.
[11] Laws, P. "Calculus-based physics without lectures," Phys. Today 44:12, 24-31 (December 1991).
| University of Maryland | Physics Department | PERG UMD |
|---|---|---|
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