Promoting Active Learning Using the Results of Physics Education ResearchPriscilla Laws
Dickinson College, USA
University of Oregon, USA
Tufts University, USA
On January 20-22, 1999 at The University of Sydney, and on January 27-29, 1999 at Swinburne University of Technology, we presented "Chautauqua" short courses on "Promoting Active Learning in Introductory Physics Courses". This article outlines the rationale for these courses, and presents brief examples of activities from active learning physics curricula developed by the Activity-Based Physics group, of which the authors are members.
Are most students in physics courses acquiring a sound conceptual grasp of basic physics principles? Extensive studies of students' basic conceptual knowledge before and after introductory college physics courses have convinced some in the larger community of physics teachers that they are not. The results of these studies show that students in selective universities, whether they be science majors or not, fail to use the same physical models as physicists when they answer the simplest conceptual questions. These same students are able to solve many traditional problems involving the solution of algebraic equations or even those requiring the methods of the calculus. Even so, they enter and leave the courses with basic misunderstandings about the physical world essentially intact. The ineffectiveness of these learning experiences seems to be independent of the apparent skill of the teacher, or whether students have taken physics courses in secondary school.
Consider traditional instruction in dynamics - force and motion - as an example of student conceptual learning in physics. Although a Newtonian framework is essential to understanding non-relativistic motion, it is common for more than 80% of students to answer most questions from a non-Newtonian point of view after an introductory physics course. Such students may believe, for example, that a net force is required to keep an object in motion at a constant velocity, that there is a residual force (impetus) on an object that has been pushed and released that keeps it moving, and that acceleration must increase as velocity increases. In contrast, those using a conceptual framework based on Newton's laws of motion understand that a body moving at constant velocity requires no net force to keep it moving and so no residual forces are required. They also understand that a constant linear acceleration produces a uniformly increasing velocity. Research has shown that traditional instruction commonly changes the conceptual point of view of only 5% to 15% of the students.
Figure 1 shows the results of composite research data for thousands of students at US universities who took the Force and Motion Conceptual Evaluation1. Such results do not only apply to the US. For example, our research at The University of Sydney in Australia shows that entering students are better prepared than many students in the US, and more believe the Newtonian model before university instruction. However, good traditional university instruction again results in only an additional 10% of students adopting the Newtonian model for force and motion.
What is needed to change the state of physics education is agreement on a set of underlying principles about the teaching and learning of physics that will support the integration of the work of many different groups into a coherent educational response based on careful research.
Figure 1. Composite assessment of US student understanding of kinematics (labeled Velocity and Acceleration concepts) and dynamics, as described by Newton's Laws (labeled Force concepts), using the Force and Motion Conceptual Evaluation. Dark bars show student understanding coming into beginning university courses, striped bars are after all traditional instruction. While the percentage of students who know concepts coming in can vary with the selectivity of the university, the effect of traditional instruction is to change the minds of only 5% to 15% of students. New methods described later in this paper result in up to 90% of students understanding concepts (lighter solid bars).
Principles for a new science pedagogy
Eleven physics education researchers from the US were assembled at Tufts University in 1992 to examine student learning in physics2. The researchers came to agreement on the following generalizations about student learning in physics and the inadequacies of traditional instruction:
Each generalization is supported by research from different sources using different techniques. These include, for example, the results from student interviews by the Physics Education Group at the University of Washington3, eliciting detailed accounts of understanding; the analysis carried out at the Center for Science and Mathematics Teaching at Tufts University on responses from thousands of students at many different institutions to research-based multiple choice and short answer questions that are part of the Force and Motion Conceptual Evaluation1; and the results on benchmark conceptual examinations designed by David Hestenes and his colleagues at Arizona State University4. It is difficult for physicists who look at the accumulating evidence to find justifications for continuing to teach in a traditional manner.
Most physics education researchers believe that students must be intellectually engaged and actively involved in their learning, and that traditional instruction is failing to provide this engagement. However, which methods of teaching and what learning contexts will help students learn most effectively? Can educational technology improve physics learning? Under what conditions does collaborative learning work well? What role should experimentation play in student learning?
Figure 2. Student walking in front of an ultrasonic motion detector while his position is being graphed as he moves. The context and importance of this simple activity is described in the text.
Example of laboratory activities using the new pedagogy
Consider a simple activity that is included in three of the activity-based, computer-assisted, guided-inquiry curricula developed by members of the Activity-Based Physics group5 - Workshop Physics6,7, RealTime Physics Mechanics8, and Tools for Scientific Thinking Motion and Force9. At the beginning of their study of motion, students first explore position, velocity and acceleration concepts using real-time graphs of body motions produced by walking in front of a "motion detector". They generally work in groups of three, are required to make predictions of experimental outcomes, and are encouraged to discuss with other group members the graphs resulting from their movements. Students answer simple conceptual questions as they work that have them describe motion verbally, in standard written language, graphically, quantitatively, and in vector representations.
What effective practices for teaching physics does this example embody? In terms of general course structures we have found student learning is improved when we:
Active learning activities in lectures
Small interactive groups working with computer-assisted data gathering are certainly not possible in all learning contexts. We have developed a method to change a classroom or a lecture hall with a single computer into a more active learning environment. The (computer-supported) Interactive Lecture Demonstrations1,10,11,12 consist of a sequence of simple experiments (6 to 8 per session) based on research of the conceptual foundation needed to learn a particular topic area in physics. The computer is equipped with data logging software, an interface and appropriate MBL (microcomputer-based laboratory) probes. For force and motion, we might use a force probe and a motion detector with low-friction carts to explore the result of various forces on the carts' motion. To examine the interaction forces in a collision between two objects, we would use two force probes. Figure 3 shows such an arrangement. An experiment in which one cart is much heavier than another is part of the Newton's Third Law Interactive Lecture Demonstration sequence. The actual results from such a collision are shown in Figure 4.
Figure 3. Arrangement for one of the experiments in Newton's Third Law Interactive Lecture Demonstration sequence. The force probes measure the interaction forces between the carts. An actual result of such an experiment is shown in Figure 4.
Figure 4. Actual result for one of the experiments in Newton's Third Law Interactive Lecture Demonstration sequence shown in Figure 3. In this case, cart 1 is three times heavier than cart 2 but just as Newton would predict, the interaction forces are equal and opposite.
In an Interactive Lecture Demonstration session students are given a "prediction sheet" with space to write their individual predictions. The sheet is collected to encourage participation. They are also given an essentially identical "results sheet" which they may fill out with the actual experimental results and keep. For each simple experiment or demonstration in the sequence, we use the following protocol.
The successes of the research-based strategies and curricula described above have been demonstrated by large conceptual learning gains in introductory courses. After traditional instruction, only 30% of a sample of over 1200 students in calculus-based physics courses at five different universities, understood fundamental acceleration concepts. When, for the first time, two Tools for Scientific Thinking active-learning kinematics laboratories were offered at these universities, more than 75% of the students understood these concepts. At universities where the complete set of RealTime Physics Mechanics laboratories have been implemented, such as the University of Oregon and Tufts University, 93% of students understand these concepts, even in non-calculus introductory courses. At such universities, less than 15% of students held a Newtonian point of view after traditional instruction in dynamics, while 90% did so after RealTime Physics laboratories. There is good evidence that this conceptual understanding is retained.
The Interactive Lecture Demonstrations1,10,11 have had similar success in changing the large lecture environment into an active environment that enables students to learn force and motion concepts. Such limited implementation of new methods is not enough, but begins to address the problem of changing instruction in traditional environments. Similar positive results are achieved in the more comprehensive Workshop Physics6,7 program at Dickinson College that has replaced lectures with a combination of student-oriented activities using similar active learning techniques and the educational technology described above.
In summary, there is considerable evidence collected by researchers in physics teaching and learning that traditional instructional methods - largely lecture and problem solving - are not effective in promoting conceptual learning in physics. There is also widespread evidence that active learning methods, some of which were described here, work well in many different environments. There is enough agreement among careful researchers that the physics teaching community would do well to use curricula and methods based on practices that have actually been demonstrated to enhance student learning. It is prudent to examine in a scientific way the learning results of these new methods in specific learning contexts. Initial results show that activity-based, computer-supported, interactive learning environments well serve the diversity of students studying physics.
UniServe Science News Volume 13 July 1999
Page Maintained By: PhySciCH@mail.usyd.edu.au