Interacting With Real-World Physics in a Web-based Learning EnvironmentMichelle Livett and Jon Pearce
School of Physics, The University of Melbourne
Background to the project
Among the challenges facing physics educators are the following characteristics of many students.
Underlying many of the teaching strategies being explored by physics teachers is the desire to assist students to recognise the powerful insights physics offers in understanding their everyday experience. We seek to help students resolve conflicts between their prior conceptions and the accepted physics view and to integrate the physics understanding they gain during formal instruction into the conceptual framework they use to understand everyday events.
In this project we aimed to tackle this challenge by providing opportunities for students to construct their own understanding of physics principles from measurement of real-world events and exploration of the implications of physics for people involved in those events.
This project developed a web-based learning environment in which students view closely, and analyse, short video segments of real-world events or key lecture demonstrations. The central feature of the environment is a Java applet, called MotionWorkshop, which the project developed for the analysis of video-clips. Use of MotionWorkshop is embedded in a library of modules that guide students' learning.
A strong thread in the design of this package is the opportunity it provides for students to visualise data in different ways. It attempts to cater for the diversity in the ways students learn by providing multiple representations of data - as video images of object positions, numbers in a spreadsheet, or graphically, together with video interview input.
Features of each module
Introduction on the web
Upon selecting a module students are presented with a web document which provides some background to the context of the motion to be explored, outlines the requirements of the module, presents a short video of the motion to be analysed and solicits feedback from the student (via a web form) concerning their initial conceptions about the physics underpinning the event. This background acts as a springboard for analysing the event. The example we focus on here is the Ups and Downs module, in which students examine the motion of three balls being juggled.
After launching the MotionWorkshop applet the student selects the appropriate video segment for analysis. Clicking on the chosen object in each frame of the video automatically enters the sequence of position data for the object into successive rows of the spreadsheet. For rotational motion it is possible to perform the analysis in polar co-ordinates.
After entering position data into the MotionWorkshop spreadsheet the student can then elect to display columns of data representing various parameters, such as velocity or acceleration, and choose the degree of smoothing to be applied when calculating these data. The video can be calibrated using the "ruler" shown in the video-clip. The student can choose to plot a graph of one or two of the quantities, and scale and/or shift the graphs to optimise their usefulness. The direction taken in this exploration is motivated by the key questions the student is seeking to answer about the motion. Throughout this process, the student makes decisions and sees their immediate consequences.
Figure 1. The MotionWorkshop screen, showing an analysis of the motion of a ball being juggled. The position-time and velocity-time graphs for the ball illustrate that the velocity changes at a constant rate and that its value at the topmost point of the ball's flight is zero.
Students use module booklets that guide their exploration of the motion, challenge them to think, to analyse, and to record their learning. The booklet provides a take-away record of students' learning. The degree of guidance varies from module to module depending on the explicit objectives of the exercise. For example, after a guided exploration of the juggling of three balls in Ups and Downs, a more open-ended exploration of the juggling of clubs is provided in Juggling Physics with Clubs.
Where appropriate, the analysis activity is coupled with "virtual interviews" with the protagonist of the video clip. By choosing from a set of questions, and viewing previously videoed replies, students gain insights into how the physics ideas apply in practice. Students can ask the juggler about how he uses a knowledge of physics (or lack of) whilst juggling e.g. "Do you have to vary the spin of the club if you want to throw it higher?" The question/answer process also allows the modules to prompt the student to further analysis.
Reflecting on learning
Students are encouraged to make reflective comments about what they have learned, the problems encountered and thoughts on the process. The booklet entries produce a record of what the student has done as well as providing feedback to us about learning outcomes and student impressions.
Modules developed so far include:
Due to the constraints of integrating QuickTime movies with Java, currently video-clips are delivered as a sequence of image files. With rapid Java developments it is expected that users will soon be able to analyse QuickTime movies, accessing the wealth of real-world movies accessible on the web, as well as their own productions.
Comparison with other strategies
Another strategy that is increasingly commonly being used to help students grasp concepts of motion is the micro-computer-based laboratory (MBL) approach. Students are able to move themselves or another object in one-dimension near an ultrasonic transducer that detects the distance between the transducer and the object. Computer software converts this information into graphs of position, velocity and acceleration that can be displayed on the screen in real time. We are in the process of comparing the nature of student learning using MotionWorkshop and this teaching strategy.
This project attracted further CUTSD funding for 1998, principally to enhance the capability of the MotionWorkshop software. Interesting real-world events are often described by vectors in three dimensions, for example rotational motion, so the spreadsheet is being expanded to include the third dimension. More important is extension of the numerical modelling capability of the spreadsheet. New modules will enable students to analyse a real motion, attempt to model the motion on the basis of physics principles, display their model graphically and then refine their model to match more closely the real motion. This refinement process is expected to contribute to a deeper understanding of the physics of the motion.
The project resources can be found at:
We have been very appreciative of the skilled Java programming of Duc Do Minh in bringing the complex MotionWorkshop applet to this stage of development. Duc Do Minh is currently the Information Technology manager of Commercial Interactive Media.
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Redish, E. F. (1994) Implications of cognitive studies for teaching physics Am. J. Phys. 62, 796-803.
Redish, E. F., Saul, J. M. and Steinberg, R. N. (1997) On the Effectiveness of Active-Engagement Microcomputer-Based Laboratories, Am. J. Phys. 65, 45-54.
Thornton, R. K. and Sokoloff, D. R., (1990) Learning Motion Concepts Using Real-Time Microcomputer-Based Laboratory Tools, Am. J. Phys. 58 (9).
UniServe Science News Volume 10 July 1998
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