DA SILVEIRA, Marcos A.1, DA SILVA, Carlos Tersio C.2
1 Departamento de Engenharia Eletrica, PUC-Rio, Marques de Sao Vicente, 225, 22453-900, Rio de Janeiro, RJ, Brasil, marcos@ele.puc-rio.br, http://www.ele.puc-rio.br
2 Departamento de Engenharia Eletrica, PUC-Rio, Marques de Sao Vicente, 225, 22453-900, Rio de Janeiro, RJ, Brasil, tersio@ele.puc-rio.br, http://www.ele.puc-rio.br
Abstract: This paper follows the paper "Hands-On Teaching And Entrepreneurship Development", presented at ICEE98. The former describes the introduction of concurrent methodology in the Electric Circuits course at the Electrical Engineering Department at PUC-Rio, an experience started at the first term of 1997. The present paper describes the student’s changes in consequence of this methodology, measured by their behavior in the courses following Electric Circuits. Due to those changes, it was not possible anymore to teach a traditional and fixed sequential course without great student discouragement. The description of these facts and of the methodology employed to face this "problem" is described in this paper.
Keywords: Hands-on methodology, concurrent methodology, engineering education.
This paper follows the paper "Hands-On Teaching And Entrepreneurship Development", presented at ICEE98 (da Silveira et al., 1998). The former describes the introduction of concurrent methodology in the Electric Circuits course of the Electrical Engineering Department at PUC-Rio, an experience started at the first term of 1997. The present paper describes the students changes in consequence of this methodology, measured by their behavior in the courses following the Electric Circuits, Electronic Devices and Linear Electronics, as observed in the second term of 1998. Due to those changes, it was not possible anymore to teach a traditional and fixed sequential course without great student discouragement. These facts and the methodology employed to face this desired problem are described in this paper.
A more complete discussion of concurrent methodology can be found in (da Silveira & Scavarda do Carmo, 1999), with its theoretical foundations and its relations to hands-on methodology. An account of PUC-Rio experiences on the subject can be found in (da Silveira et al., 1999).
Some students attended the Electric Circuits course when the hands-on methodology was introduced; in fact it was a mix of sequential and concurrent strategies. The theory was presented sequentially and the laboratory started with classical practices covering the properties and behavior of circuits, as shown in the theory. At the same time, the students were ideologically prepared for the changes in the course and a responsible and engaged attitude was demanded from them. After this initial part, the laboratory work changed to a new form: it was asked from the students to develop an electric device (a low power no-break). This work was done by groups of students, in competition, who had to present the final result of their work (project, simulation and a prototype) to an examining board of professors and engineers from Siemens company.
This project was where the concurrent methodology of teaching was used: the students had to choose the appropriate electronic devices, design simple linear circuits and, as desired, take the initiative in the project. As the work demanded more than what was shown in theory, the students had to look for solutions, ask other people and even learn related topics.
As soon as the courses on Electronic Devices and Linear Electronics started the teachers noticed the difference in behavior among the students: one group, which had taken Electric Circuits as stated above, was curious about the subject to be discussed in class (due to their previous experience in the project) while another group, which had a traditional Electric Circuits course, had some difficulty in following the classes.
Therefore, the instructors had to face two facts: on one hand, it was not possible to go back to the traditional teaching method because it would invalidate all the work previously done and, on the other hand, there was a group of students which could not respond to the new course because they were not prepared for that. Considering the methodology, there were two aspect of the experience to be considered. The first fact was that the concurrent method resulted in a better response from the students and, therefore, its application in other courses should be considered. The second point to be considered was how to teach a course using this new method without discouraging the class, when part of the students were not prepared for it.
The solution to this problem is not unique; it is possible, for instance, to divide the students in two groups and give them separate training. Another way of circumventing the problem was adopted: the course started with a brief revision of the topics which part of the students hadn’t seen before. After that revision, the course came back to its new fashion. The laboratory work still is quite similar to the traditional one. However, it has one new feature: each circuits is explored to its limits so that the students can verify the effect of device limitations; as each problem appeared, the instructor questioned the students to find a theoretical explanation to what they were verifying in practice.
Whenever it was considered of interest the theory was covered starting from examples and problems to be solve by the students, working in groups. A better explanation of the instructor behavior is presented in (da Silveira & Scavarda do Carmo, 1999).
The courses of Electronic Devices and Linear Electronics had, also, their contents changed by the same time this experiment was conducted in Electric Circuits. Previously, each course covered part of the topics in linear electronics. The change consisted in presenting all topics in both courses but, while in Electronic Devices this coverage was not deep, the Linear Electronic course took advantage of the fact that the students had a previous knowledge of all topics and used that to interconnect them and present new circuits and applications to the students. As an example, since they knew something about operational amplifiers, power supplies and diodes, the instructor could introduce the idea of using these amplifiers and diodes to build wide-band rectifiers.
Each of these courses, besides the small projects developed in class, also had a final group project. One of the facts that were noticed was that the students had accepted the use of simulators. All groups simulated their projects by their own initiative before trying them in the laboratory; the simulator programs varied but most of the groups use TSpice or Benchwork.
The instructor proposed three projects: a power supply, a wide-band amplifier and a function generator. Each group could choose its project or propose new projects (one group proposed, and it was accepted, to design and build a guitar amplifier). The work consisted of the design, implementation of the circuit and a final report. The report, besides showing all calculations, had to include a cost budget (considering taxes, direct and indirect expenses and an estimate of final price for the equipment). The course evaluation consisted of a weighted average of all grades from tests, a final examination, laboratory and the project.
There was a flaw in the project and it was the instructor fault. He did not fix a chronogram - nor asked the students to propose one - and, as a result, the projects were turned in late.
All prototypes built by the students worked - even the audio amplifier, which was presented in a guitar show - but the project goals were not completely achieved. Some reports were not as complete as desired; only one group presented a cost budget. This showed the need for a better organization and a rigid chronogram.
The best-prepared projects usually came from students who were already familiar with the concurrent teaching method. However, some students who had not taken the new course in Electrical Circuits also did a nice work.
The comparison between the traditional and the new way of presenting the course material is not quite simple because there are too many factor involved. However, it seems that:
The consequence from this experiment was the need to change the goals of these disciplines. It is not enough to make the student capable of designing electric equipment. The student has, also, to be sure - at a practical level - that he/she can, indeed, do it.
The course and methodology subjective evaluations were good but there is not, at the moment, numerical data to present. However, it is our feeling that this is the correct path in the education of the next century engineers.
M. A. DA SILVEIRA, M. SCHWANKE, M. R. DE FREITAS, C. R. KELBER. Hand’s-On Teaching and Entrepreneurship Formation: An Example on Electrical Circuits Courses. In Proceedings of the ICEE98. Rio de Janeiro: PUC-Rio, 1998, CDROM.
MARCOS A. DA SILVEIRA, LUIZ C. SCAVARDA DO CARMO. Sequential and Concurrent Teaching: Structuring Hand’s-On Methodology. In IEEE Trans. Education, 1999. To be published.
M. A. DA SILVEIRA, J. A. PARISE, T. A. COSTA, L. A. MEIRELLES, M. SCHWANKE, L. C. SCAVARDA DO CARMO. A Summary of Experiences on Concurrent Teaching at PUC-Rio. Internal Report CTC/PUC-Rio. Rio de Janeiro: PUC-Rio, 1999.