|
Article Excerpt
Teaching physics in the laboratory, and more specifically, the use of computers in the physics laboratory is a question of worldwide concern. In this article the authors shall try to validate the use of microcomputer-based laboratories (MBL), based both on theoretical and empirical grounds. Furthermore, an example of an MBL in introductory kinematics is proposed.
**********
In 1998, a brief discussion was held in the Physics Learning Research List, arising from some questions asked by one of the participants, Marcelo Robles Castillo (1998):
I am new in this List and I want to know if you have discussed previously the use of computers in Lab. I think computers are not as useful there as many people may think. Perhaps if the experience is carefully designed... But students don't understand what is going on; they only see numbers or graphs, usually teachers don't operate correctly the PC and sensors, and at depth, what are now the objectives of the activity of laboratory in Physics? (Anyway, what are the classical objectives of lab in Physics?).
Yes, I know, I like Lab too. But without an emotional argument, why do we teach at Lab? And why do we use computers? Are there any references somewhere?
Some of the participants in this physics education research list provided their colleague with several important references, both published or online manuscripts, but the most interesting response came from Dr. Pratibba Jolly (1998):
The "list" of nice experiments that can be set up in the laboratory is fairly large - most of them do yield neat data. (See for instance the work of Thornton & Sokoloff (1990), Priscilla Laws (1997), and many others).
The problem is replicating these in your laboratory. That requires apart from the requisite hardware and software (often multiple copies of expensive setups), a lot of experience. And you are right, of course, the full battery of Murphy's laws gets activated any time you try even a simple computer based experiment. In India (also Chile?) we don't have PASCO, VERNIER, et al. supplying the essential hardware/software and so there is the additional challenge of learning enough to build it all up. The question then is: Is it worth the effort? I am convinced it is.
As can be seen from this short discussion, teaching physics in the laboratory, and more specifically, the use of computers in the physics laboratory is a question of worldwide concern. In the following sections the authors try to validate Dr. Jolly's assertion, based both on theoretical and empirical grounds. Furthermore, an example of an MBL in introductory kinematics is proposed.
THE TRANSMISSION MODEL OF INSTRUCTION
Laws (1997), the coordinator of the Workshop Physics Project at Dickinson College (Pennsylvania), quoted Millikan's words dating more than 100 years ago:
I had become thoroughly disillusioned by the ineffectiveness of the large general lecture courses of which I had seen so much in Europe and also in Columbia, and felt that a collegiate course in which laboratory problems and assigned quiz problems carried the thread of the course could be made to yield much better training, at least in physics....I started with the idea of making the whole course selfcontained....I abolished the general lectures...This general method of teaching...has been followed in all the courses with which I have been in any way connected with. (Millikan, 1950)
Millikan's conclusions about the ineffectiveness of lectures in introductory physics courses have been reconfirmed by Bligh's (1978) more recent research on the impact of lectures in over 200 college-level courses of all types. Bligh concluded that lectures are best for inspiration and for the transmission of information but they are not effective for teaching concepts.
Nevertheless, the prevalent practice found today in physics education results from the so-called transmission model of instruction. In this model, students are exposed to content mainly through lectures and are expected to absorb the transmitted knowledge in ready-to-use form. Although it is not a model of learning per se, the transmission model does make a crucial assumption about learning, namely that the message the student receives is the message the teacher intended (Mestre, 1991).
The transmission model is used largely by default, both because it is the instructional method by which we were taught and because it may be the only instructional method most teachers know. Educational research (Driver, Guesne, & Tiberghien, 1985; Peters, 1982; Mestre & Touger, 1989) shows that the traditional science instructional method is ineffective in altering student misconceptions and simplistic understandings. Even at the university level, students continue to hold fundamental misunderstandings of the world about them: any science learning remains within the classroom context and has no effect on their thinking about the larger physical world, independent of the apparent skill of the teacher (Halloun & Hestenes, 1985a). Thornton (1987) claimed that even successful students who can solve all the problems at the end of a chapter generally lack physical intuition.
THE CONSTRUCTIVIST MODEL OF INSTRUCTION
Unlike the transmission model, the second major instructional practice, which has emerged over the last two decades, begins with what is commonly termed the constructivist model of learning, or simply constructivism. A constructivist model of learning assumes the existence of learners' conceptual schemata and the active application of these in responding to and making sense of new situations. Science education researchers have adopted Kelly's theory of Personal Constructs (as cited in Pope & Keen, 1981) as a viable means of constructivist theory because his approach is based on the metaphor of "a man as a scientist."
Watts and Bentley (1987) claimed that constructivist theories of learning understand processes of conceptual change in school science as being motivated by dissatisfaction with students' existing ideas in the face of empirical evidence, images, analogies, or instruction. The change appears to occur where students are encouraged to make their own ideas explicit so that ensuing explorations will find them wanting (Strike and Posner, 1985).
Hewson and Hewson (1984) claimed that, for a conceptual change to take place, instruction should reduce the plausibility of the existing conceptions by illustrating how those conceptions are not satisfactory and then encourage the acceptability of the new conception. The motivation for change arises when the student recognizes that the new conception is more fruitful than the old ones.
Use of teaching strategies, which influence conceptual change, could positively affect student performance. The constructivist approach is based on a view of learners as active and purposive in the learning process and involved...
|
