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Article Excerpt
Several Canadian universities and colleges have been working together for years to build Web-accessible computer-based applets to help students learn physics concepts. This paper reports the findings from a study that evaluated the effectiveness of these applets in enhancing conceptual learning. We integrated quantitative and qualitative methods including tests, surveys, focus groups, interviews, and class observations. The data show that the computer-based applets, which were designed in the light of constructivism, were helpful in fostering conceptual learning, but they should be used in a constructivist teaching environment to be more effective. In addition, based on this study, some suggestions will be given on the use of instructional technology in teacher education.
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INTRODUCTION
Conceptual learning has been considered an important topic; much effort has been made to improve physics instruction and to thus help students to better understand concepts (Brouwer, 1995; Redish, Saul, & Steinberg, 1997; Redish & Steinberg, 1999; Thornton & Sokoloff, 1990). Since the spring of 1998, several Canadian universities and colleges have been working together on an ongoing project, known as the "Modular Approach to Physics (MAP)," to help students learn physics concepts. A set of Web-accessible applets has been built. Each applet is focused on one key concept of university first-year physics, and is made up of one or more than one simulations designed in the light of constructivism.
The evaluation of the MAP applets started in 1999 with a pilot test. More formal investigations followed in 2000. This paper focuses on our findings on two questions: (1) Are the MAP applets effective in enhancing conceptual learning? (2) In what teaching environment are these applets more effective? In addition, we also discuss some issues related to teacher education based on our research findings.
CONSTRUCTIVIST APPROACH TO SCIENCE TEACHING
Constructivists take knowledge as a construction by human beings rather than as an absolutely true representation of the world; therefore, they believe that effective learning should be an active process during which students construct and reconstruct the knowledge (von Glasersfeld, 1995). This new interpretation of learning asks us to make a shift in instruction from "what are we teaching and how can we deliver it?" to "what are the students learning and how do we make sense of what they do?" (Redish & Steinberg, 1999)
In the last three decades, intensive studies in science education have demonstrated that students come to school with their own understandings of the world, which greatly influence their learning (Driver, Guesne, & Tiberghien, 1985). Although, in some instances, student preconceptions are in keeping with scientific ones, most often there are huge differences between children's notions and school science. Therefore, how to facilitate the movement of students from intuitive understanding to scientific understanding becomes a key question for science educators.
The ontological study of student preconceptions tells us that many students' preconceptions are reminiscent of well known concepts in the history of science. For example, "a heavier body falls faster than a lighter one," "force can be given to an object under the name of 'impetus," and "force is needed to maintain motion," are conceptions held by people and scientists in pre-Newtonian times and are well documented in the studies of students' preconceptions (Berg & Brouwer, 1991; Clement, 1982; Driver & Easley, 1978; McCloskey, 1983). "Heat is a kind of material that can flow from one object to another" (Erickson, 1979, 1980). This preconception reminds us of scientists' caloric view of heat in the 19th century. The parallelism between the history of science and the psychological process does not exist only at this content level. Scholars are trying to convince us that there is also a parallelism concerning the general features of the process of knowledge acquisition in the history of science and by students. Gopnik (1996) claimed that the fundamental cognitive processes are the same in students and mature scientists. Siegel (1995) further maintained that students like scientists need to assess their own ideas before any new view can be accepted.
The hypothesis of a parallelism between the process of student learning and the development of science has been a fruitful source of pedagogical study. Paralleling the conditions suggested by Kuhn for scientific revolutions (Kuhn, 1970), Posner, Strike, Hewson, and Gertzog (1982) state that several important conditions must be fulfilled before any conceptual change occurs. These conditions can be briefly described in terms of students' dissatisfaction with the old conception and the intelligibility, plausibility, and fruitfulness of the new conception. Although Posner's model is criticized as a 'cool' or 'isolated' model because it ignores the social dimension and the non-rational aspect of learning (Pintrich, Marx, & Boyle, 1993), it correctly addresses the importance of cognitive conflict in conceptual change. Many instructional strategies proposed to address students' preconceptions, such as "Prediction-Observation-Explanation," share a common feature--they confront students with discrepant events that contradict their conceptions (Scott, Asoko, & Driver, 1992). This is intended to invoke cognitive disequilibration that induces students to reconstruct knowledge. Discrepant events can be demonstrations that require students to make predictions or phenomena that require students to explain why and how.
Computer simulations can also be used to provide such discrepant events. To have this function, computer simulations should be able to allow students to interact with the process, make predictions, and test their predictions. With these kinds of simulation, students can freely explore the microworld the program creates by changing parameters and variables; they can immediately visualize the consequence of their manipulations.
There are not many studies that have been done primarily about the effectiveness of computer simulations on conceptual change, and the reported studies have drawn an unclear picture on this topic. For example, Zietsman and Hewson (1986) used a computer simulation to diagnose and remedy alternative conceptions about velocity. Their results indicate that computer simulations can be a credible representation of reality and that the use of simulation produces significant conceptual change in students' alternative conceptions. Carlen and Andre (1992), however, in a study on electrical circuits, found that using text designed to produce conceptual change resulted in better performance on tests, but that using a computer simulation in addition to the text produced no greater change than the text alone.
We assume that the effectiveness of computer simulations is determined by two factors: the simulation design and the context in which simulations are used. In this study, we have used our...
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