The Distribution and Change of Student Expectations in Introductory Physics

Edward F. Redish, Richard N. Steinberg, and Jeffery M. Saul

Department of Physics, University of Maryland, College Park, MD 20742-4111

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.

Abstract

Students not only bring their prior understanding of physics concepts into the classroom, they also bring to their physics class a set of attitudes, beliefs, and assumptions about the nature of physics knowledge, what the students are to learn, what skills will be required of them, and what they need to do to succeed. These "expectations" can affect not only how students interpret class activities, but also from which of these activities the students build their understanding and the type of understanding they build. We report here on the development of the Maryland Physics Expectations (MPEX) Survey, a Likert-scale survey to probe these expectations. Observations of more than 1000 students at 5 institutions in first semester physics classes show that many students have expectation misconceptions about the nature of physics and what they should be doing to learn it. Furthermore, the effect of the first semester class is to deteriorate rather than improve these expectations.

I. INTRODUCTION

What students expect will happen in their introductory calculus-based (university) physics course plays a critical role in what they will learn during the course. It affects what they listen to and what they ignore in the firehose of information provided during a typical course by professor, teaching assistant, laboratory, and text. It affects what activities students select in constructing their own knowledge base and in building their own understanding of the course material.

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.

II. TEACHING CONCEPTS

In the past fifteen years there has been a momentous change in what we know about teaching and learning in the introductory calculus-based physics course.[3] In studying student understanding of the basic concepts of physics, much has been revealed about what students know and how they learn. One critical element is that students are not "blank slates." Their experience of the world (and of school) leads them to develop many physics concepts on their own. These concepts are often not in accord with those that are being taught in the physics course, and this makes it difficult for students to build the conclusions the teacher desires. However, it has been demonstrated that if one takes account the students' initial states, it is often possible to provide activities that induce most students to develop a good functional understanding of many of the basic concepts.[4]

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?

III. STUDENT EXPECTATIONS

It is not only physics concepts that a student brings into the physics classroom. Every student, based on his or her own experience, brings to the physics class a set of expectations -- attitudes, beliefs, and assumptions -- about what sort of thing they will learn, what skills will be required, and what they will be expected to do. In addition, many of them will have a view as to the nature of scientific information that affects how they interpret what they hear. In this paper, we use the phrase student expectations to cover this rich set of understandings. We focus on student expectations about the context they bring to their learning rather than about the content they are studying.

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]

Table 1: Dimensions of Student Learning
Favorable CharacteristicsUnfavorable Characteristics
beliefs about learning physics:takes responsibility for constructing own understandingtakes what is given by authorities (instructor, text) without evaluation
beliefs about the content of physics knowledge:stresses understanding of the underlying ideas and conceptsfocuses on memorizing and using formulas
beliefs about the structure of physics knowledge:believes physics needs to be considered as a connected, consistent frameworkbelieves 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 contextsbelieves 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 phenomenaviews 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.

IV. THE MPEX SURVEY

We have investigated student expectations using a variety of methods. Interactions with students in the classroom and in informal settings over many years provided preliminary and continuing insights into student expectations. In addition, in Autumn, 1992, we began to develop an attitudinal survey. Students were given a variety of statements about the nature of physics, the study of physics, and their relation to it. They rated these statements on a five point scale from strongly disagree (1) to strongly agree (5). Examples of survey items related to each dimension are included in Table 2.

Table 2: Sample Survey Items
Student Learning DimensionRelated 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]

V. RESULTS

In this section we display a few of the results of our survey. More details will be given in a forthcoming paper.[10] The participating institutions whose results are reported here are given in Table 3. Classes reported in this presentation used either the traditional model (lecture + recitation + lab) or Workshop Physics.[11]

Table 3: Participating Institutions
InstitutionClass Description (number of classes surveyed)N (matched)
University of Maryland (College Park)traditional (8)445
Prince George's Community Collegetraditional (4)44
Dickinson CollegeWorkshop Physics (4)75
Moorehead State UniversityWorkshop Physics (1)12
University of Minnesotatraditional (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 experts consider disagreement with the first and third and agreement with the second and fourth items to be favorable.

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

We note that most classes start off with a strongly favorable response. On the average, 70% of the students see physics as relevant and related to the real world. The result of the courses measured (even a strongly hands-on course such as Workshop Physics) leads to a significant deterioration of student attitudes in this dimension. Interviews confirm that, if the connection is not specifically made with student experience and with examples they see as relevant, students often see the physics done in class as pertaining only to specially prepared situations or the classroom.

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

VI. CONCLUSIONS

Our results suggest that students come into our courses with expectations that do not match those of the instructor and that typical courses, both traditional and designed to help build concepts, do not improve many of these attitudes. Using research to develop curriculum has met with some success in addressing student difficulties with conceptual understanding and problem solving, including in courses in this study. This type of work will have to be extended and evaluated along new lines in order to address the difficulties reported in this paper.

ACKNOWLEDGEMENTS

We would like to thank the faculty at Dickinson College, Prince George's Community College, Moorehead State University, and the University of Minnesota who permitted us to distribute our survey in their classes. We would also like to thank Michael Wittmann and Mel Sabella for useful comments on this paper. This work was supported in part by NSF grant RED-9355849.

References

[1] Carey, S., Evans, R., Honda, M., Jay, E., and Unger, C., " 'An experiment is when you try it and see if it works': a study of grade 7 students' understanding of the construction of scientific knowledge," Int. J. Sci. Ed. 11, 514-529 (1989).

[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).

RETURNS

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email:redish@quark.umd.edu
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