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Macromedia Flash Animation: Interactive Learning in Introductory Online Electrical Engineering Courses MANI SOMA, EVE A. RISKIN, JENNIFER HARRIS, LAURA J. COLLINS, BEE NGO, and EDDY FERRÉ University of Washington, Department of Electrical Engineering and Office of Educational Assessment, Seattle, WA 98195-2500. Email: riskin@ee.washington.edu. Student demand for online courses in higher education has increased exponentially in the last decade. To meet this demand, interactive web pages have been developed for undergraduate electrical engineering online courses using Flash animation for key concepts such as steady-state analysis, time scale, time reversal, and convolution. The integrative capacity of this curriculum allows students to be active participants in their online learning. Through student input and immediate feedback in solving electrical engineering exercises in a systematic, step-by-step way, students can comprehend and visualize difficult electrical engineering concepts. INTRODUCTION Distance education has advanced rapidly since its inception with correspondence courses of the nineteenth century, whose delivery was augmented by the development of radio, television, and other media in the twentieth century. In the most recent decades, "providing education at a distance has changed significantly as the use of computer- mediated learning, two-way interactive video, and other technologies has increased" [1]. However, it is important to point out that the development of computer-mediated communication is not synonymous with collaborative learning, but it is a necessary precursor. Computer-mediated coursework can continue to follow a traditionally limited teacher-to-students or student-to-teacher interaction model. However, contemporary online coursework largely follows more collaborative approaches. Benigno and Trentin [2] discuss the social nature of learning that characterizes the current third generation of distance learning: The factor that distinguishes third-generation distance education (online education) from previous forms is that the learning process is social rather than individual (Nipper, 1989). This has been brought about by the use of computer conferencing systems, which allow the creation of virtual environments that foster interpersonal communication and collaborative learning. Vogt et al. [3] note that "the web has the potential to become a tremendous learning resource on which instructional designers expect to capitalize in order to deliver large amounts of information in a student-centered, non-linear manner while allowing for multiple alternative inputs from online classmates as well as from classroom and/or distant instructors." They go on to enumerate three key features that set web course delivery apart from traditional on-site delivery. These include: 1) the web's ability to make use of hypertext links that allow the learner to navigate the flow of information; 2) its ability to incorporate multi-media learning including audio, video, and animation; and 3) the web's ability to support "high levels of learner interactivity" [4]. While distance learning technology continues to develop at a rapid fire pace, literature is lacking on the quality of these new media. As part of the Hands-on Laboratory-driven Electrical Engineering Curriculum (Pandora) project, web pages have been developed for two introductory Electrical Engineering (EE) courses – EE233 Circuit Theory and EE235 Continuous Time Linear Systems -- using the widely available Macromedia web tool set. The goal of this web page design is to allow students to direct the path of their learning by providing immediate feedback on problem solving. This article describes the unique use of Flash animation to support student learning of even the most difficult EE concepts, and reports the results of a student focus group concerning the evaluation of the material. DEVELOPMENT PHILOSOPHY We developed a framework to teach systematic problem-solving skills and allow students to complete interactive exercises at their own pace. Conventional web-based exercises tend to take two major forms: multiple-choice questions and short problems asking students to fill in numerical answers. The multiple-choice question format, even in a regular classroom, tends to encourage guessing or elimination to arrive at the correct answer. While the ability to guess or to eliminate incorrect answers is desirable, the lower-level courses need to teach students how to use basic theory to arrive at the correct answer. The implementation of this format on the web leads to another undesirable learning characteristic: students can get to the correct answer after several wrong clicks without even guessing. There is essentially no learning involved in this fast-click exercise. The short-problem format, with filled-in boxes, avoids these drawbacks but fails to teach students how to proceed step-by-step from the problem statement to the correct solution. The systematic problem-solving skill is the major learning outcome of low-level engineering courses, and web-based instruction needs to provide methods to teach this skill. Our web-based instructional methodology focuses on teaching this systematic problem-solving skill. We will illustrate this method by an example and then discuss the salient characteristics embodied in this development. The example selected is from basic circuit theory: how to do an inverse Laplace transform using the partial-fraction expansion method. Figure 1 shows the case of an inverse transform of F(s) where F(s) has distinct real roots. The blue boxes need to be filled in by signs (+ or -), the gray boxes need to be filled in by correct terms (numerical values or symbols as appropriate to a specific exercise). The yellow Drag box contains the signs, numbers, and symbols that can be dragged in to fill these blue and gray boxes. Note the Drag box may contain more terms than necessary or incorrect terms. Step 1 of the procedure involves solving for the roots of the denominator, and a student does so by dragging a term to a box. The interactive interface provides immediate feedback (“Good”) or (“Try again: you have 3 tries left”). If the student proceeds with filling correct terms, the interface comes up Step 2 with the next screen (Figure 2) to compute the first residue. As long as the student solves each step correctly, he/she proceeds to the next steps (finding all residues) and finally solves for the time function f(t) (Figure 3, Step 5 of the solution procedure) using the same Drag-and-Fill method. Figure 1. Step 1 of inverse Laplace transform procedure. Figure 2. Step 2 of inverse Laplace transform procedure. Figure 3. Step 5 of inverse Laplace transform procedure. The salient characteristics of this interactive teaching tool are: 1) No guessing or elimination as in the multiple-choice format. 2) Systematic step-by-step proceeding from the problem statement to the final answer. 3) Proper signs (+ or -) are checked for every term. The problem with incorrect sign plagues many students in the low-level electrical engineering courses. 4) Immediate feedback on each operation for correctness, so that a student does not get frustrated by proceeding down an incorrect path for a long time before discovering his/her error. 5) Avoiding students’ frustration by providing the correct answer after three tries. A lazy student of course would click randomly three times to be given the correct answer, but no tool would be able to teach a lazy student not to be so lazy! From the software design perspectives, the interactive teaching tool is written to be easily extensible without labor-intensive coding or recoding by the developers. The Drag box, containing both the correct and incorrect terms, limits the answer space so that the procedure to check for correct answers is bounded and the checking operation can be quickly performed. The checking procedure accepts the commutative property of many operations (e.g. b+c and c+b are both valid answers). This framework can be easily extended to teach many engineering concepts in various courses in EE or other disciplines. We employed this framework for both of our courses, and will discuss one particular extension below in the section on the Circuits Course to demonstrate the generality and power of this interactive teaching framework and method. THE CIRCUITS COURSE This course covers circuit analysis and design: sinusoidal steady-state, Laplace transform, basic filter designs, Bode diagrams, and two-port networks. Students learn how to analyze a given circuit using the basic Kirchhoff Voltage Law and Kirchhoff Current Law to calculate the output signal, power, transfer function, etc. Students learn how to design from specifications by choosing a circuit topology and component values to make the circuit work as specified. Systematic problem-solving skills are emphasized. The fundamental problems faced by the instructor in these courses, whether on-line or not, are: 1) How to ensure that students learn the systematic problem-solving skills. 2) How to provide enough exercises for the students to practice without using up too much class time or quiz-section time. 3) How to create more practice exercises quickly, especially if the textbook has been in use for some time (students know all the answers of the exercises in the text!). 4) How to give feedback to individual students without enormous time commitment by both the instructor and the teaching assistant(s) (TA). The interactive teaching tool described in the Development Philosophy section above is an ideal mechanism to deal with these problems. For the on-line students, immediate individual feedback is extremely critical since there are no local instructors, TAs, or peer students to help. For this course, we have developed several interactive exercises (3 to 5 per topic) for these topics: steady-state analysis, steady-state power calculation, Laplace transform method in circuit analysis, transfer function computation, Bode plot method, basic filter analysis and design, and basic two-port network parameter computation. The interactive framework has been extended to provide practice exercises for students to perform Bode plots, a topic considered difficult by students in the course. Figure 4 illustrates Step 3 (the first two steps guide the students in the derivation of the transfer function) where the student is asked to do the plot itself using this interactive learning framework. Note that the yellow Drag box now contains lines with various slopes. Initially the plot area is blank (Figure 4) and as the student drags in the lines (one line per term) and places them at the appropriate pole and zero locations, the plot is filled in term-by-term. Figure 5 shows the plot with several lines that a student has dragged into the plot area. Once a student has dragged in correctly all the individual lines, the interactive tool shows the final Bode plot (red line in Figure 6) while still keeping the individual lines (gray color) so a student can review and evaluate his/her learning in this exercise. This example shows the extension and the power of our interactive framework to teach not just formulas and calculations but also a wider range of concepts including graphical analysis and design. Figure 4. Screen to begin Bode plot (after derivation of transfer function). Figure 5. Screen with several terms plotted by students. Figure 6. Final Bode plot. THE LINEAR SYSTEMS COURSE For the Continuous Time Linear Systems course, Flash was initially used to create buttons that the students can push to see demonstrations of concepts such as time reversal, time scale, and sampling. Through the use of this technology, students can actually see the signal as it is reversed in time, sped up, slowed down, or sampled. One drawback of this approach is that even though the students can view the steps of problem solving, they are not being asked for input. To improve on this model, the framework used for the circuits course was extended to the linear systems course. Students use the same methods to work through problems systematically, this time with students inputting answers at each step. This again allows the students to be active in constructing their knowledge and puts the “onus on learning on the students” [5]. A powerful example of the application is for learning the concept of continuous time convolution, typically one of the most challenging topics for students that is covered in this course. The biggest difficulties in understanding are 1) determining the regions where two functions overlap and 2) setting up the convolution integral. We use a series of figures to show how a student would work through a convolution example. In Step 1, the student picks a function to time reverse and shift. In Step 2, he/she must identify the shift parameter on the time-reversed function (Figure 7). In Step 3, the student determines the number of regions in which the convolution integral has a different format and the values of the output parameter t for which the different regions are valid (Figure 8). In Step 4, he/she sets up the convolution integrals for each time region with the correct functions and limits of integration using our Drag-and-Fill technology (Figure 9). Finally, he/she evaluates the integral. As in the circuits examples, all answers are checked for correctness at each step and three chances are allowed before the correct answer is given. Figure 7: In Step 2, the student is asked to identify the value of on the signal that has been time-reversed and shifted. Figure 8: The student determines the number of convolution regions and the limits on the regions in Step 3. Figure 9: The student uses Drag-and- Fill technology to set up the convolution integral in Step 4. EVALUATING THE ONLINE MATERIALS To evaluate the Flash animation, the UW Office of Educational Assessment (OEA) conducted a focus group session with five undergraduate engineering students. It was felt that these students would be able to provide a unique perspective on the online course materials because they were familiar with the content and were able to compare their in class experience with the online course. Including evaluation in initial stages of innovation contributes to high quality materials and also allows program leaders and curriculum developers to make changes early on in the process [5]. Students responded positively to the Flash animations included in the lessons they reviewed. Overall, the students thought the animations enhanced the functioning of the site. They believed that these were fun and a good way to learn concepts [6]. CONCLUSION AND FUTURE DIRECTIONS There is a need to continue the development of online courses for students who are “at a distance” from college campuses or for those whose schedules conflict with on- campus course offerings. UW faculty and research assistants are continuing to develop additional demonstrations using Flash animation, including extending the demos from continuous time linear systems to discrete time linear systems. The first course using Flash animations will be piloted in the 2002-2003 academic year, with interviews of students used to evaluate the materials and course outcomes. Interested parties can view the EE233 and EE235 web pages at: http://faculty.washington.edu/manisoma/fipse/ ACKNOWLEDGEMENTS The contents of this paper were developed under a grant from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education. However, these contents do not necessarily represent the policy of the Department of Education, and you should not assume endorsement by the Federal Government. This work was presented in part at Frontiers in Education 2002. Address email inquiries to riskin@ee.washington.edu. REFERENCES 1. Phipps, R. and Merisotis, J., What's the Difference?: A Review of Contemporary Research on the Effectiveness of Distance Learning in Higher Education. The Institute for Higher Education Policy (1999), p. 1. 2. Benigno, V. and Trentin, G., "The Evaluation of Online Courses," Journal of Computer Assisted Learning, 16, (2000), p. 260. 3. Vogt, C., Kumrow, D., and Kazlauskas, E., "The Design Elements in Developing Effective Learning and Instructional Web-sites," Academic Exchange, winter, (2001), p. 40. 4. Ibid, p. 42. 5. Hawkes, M., “Criteria for Evaluating School-based Distance Education Programs,” National Association of Secondary School Principals Bulletin, (1996). 6. Harris, J., Sannicandro, T., & Collins, L., “Hands-On Laboratory-Driven Electrical Engineering Curriculum: Student Review of Online Material,” OEA Program Evaluation Division Report, (2001). BIOGRAPHIES Mani Soma is Professor of Electrical Engineering at the University of Washington and Principal Investigator on the Pandora Program. His research interests include VLSI and fault-tolerance testing. Eve Riskin is Professor of Electrical Engineering at the University of Washington and co-Principal Investigator on the Pandora Program. Her research interests include image compression, signal processing, and issues pertaining to women faculty in Science, Engineering, and Mathematics. Jennifer Harris is a doctoral student in Educational Leadership and Policy Studies at the University of Washington (UW) and a research assistant with the Office of Educational Assessment at UW. Laura J. Collins is the Lead for the Program Evaluation Division of the UW Office of Educational Assessment. Her research interests include efforts to improve teaching and learning. Bee Ngo received the Bachelor's degree in Electrical Engineering at the University of Washington in 2002. Eddy Ferré received the Bachelor’s degree in Electrical Engineering from the University of Washington in 2002. He is currently enrolled as a graduate student in EE at UW.