Improving Learning in an Electrical Engineering Programme Through a Team-Based Approach

Improving Learning in an Electrical Engineering programme through a Team-Based Approach

Jonas A S Redwood-Sawyerr

Session 4, Track 1

Improving Learning in an Electrical Engineering programme through a Team-Based Approach

Abstract

Background and motivation

The modules of Signal Analysis (EENG 411) and Computer Aided Design (EENG527), with applications using the Electronic Workbench software, have often been seen by students in the fourth and fifth years of a five year degree programme in Electrical and Electronic Engineering at Fourah Bay College, University of Sierra Leone, as difficult to understand and relate to, over several years of teaching, and the low grades obtained have always caused concern, especially the module EENG 411. This module is essentially an introduction to engineering applications of a number of mathematical concepts treated in earlier years in various modules offered by the Department of Mathematics. It was originally titled Advanced Engineering Mathematics but had to be changed when over the years, the Mathematics Department insisted that all modules carrying the name Mathematics must either be taught or supervised by them. The Faculty of Engineering was strongly opposed to this directive as it was felt that the engineering content in the concepts treated where missing or poorly appreciated by Mathematics purist in the Faculty of Pure and Applied Sciences under which the Mathematics department is housed. This then resulted in time being spent in re-orientating students to these applications when the mathematical tools required where being referred to in various analyses in later levels. In order to own the module the name was changed and greater emphasis was then placed in providing engineering applications to the concepts treated as presented by engineering lecturers.

Problem identification resolution

Many reasons were proffered for the difficulties experienced by students among which were :

• Poor comprehension of the mathematical concepts involved
• Poor presentation of the engineering appreciation of mathematical concepts taught by the Mathematics Department
• Compartmentalisation of concepts by students and poor application to engineering situations
• Not enough time given to practice examples.

On the other side of the spectrum interviews and informal discussions with graduates of the programme revealed the following comments :

• Too much content and little time for practice of problems
• Examination questions too lengthy and demanding
• Not enough tutorials

Reflection on these comments over the years led to investigation and experimentation of other teaching methods to enhance students’ learning capacity. The module in Signal Analysis was reviewed and some of the topics were transferred to the introductory part of the Control Theory module in Year V as these were pre-requisite concepts for the state variable approach to control system analysis, a topic treated in Year V. The most effective was the introduction of some aspects of team based learning in the teaching of these modules.

Conclusions and significance

• The confidence of students has grown in tackling the concepts and the phobia for this module has waned.
• Students look forward to the team-based tutorials as they provided an avenue for exchange and discussions of concepts towards better understanding of the concepts as well as better grades for continuous assessment.
• Better results are now obtained by students in these modules at the examinations

The paper discusses these experiences and the results they engendered over a period of observation.

Keywords : Analysis, students, learning, team, design.

Introduction

Sierra Leone lies in the west coast of Africa with a land area of 72,325 km2. It shares borders with the Republic of Guinea in the north-east, the Republic of Liberia in the south-east and is along the North Atlantic Ocean in the west. The current population is 4.6 million with a growth rate of 2.9%. It lies between latitudes 7o and 10o North and longitudes 10o 30’ and 13o 15’ West.

Background

University education in Sierra Leone started in 1827 when the Church Missionary Society (CMS), London, founded FourahBayCollege basically for the purpose of training Africans as schoolmasters, catechists and clergymen. In 1876, the CMS succeeded in getting the College affiliated to Durham University, U.K., which meant that the students could sit for Durham's matriculation examinations and take Durham University degree examinations, although Durham had no control over the appointment of lecturers and lecturing. The affiliation led to a revision of the courses to include Latin, Greek, Hebrew, Arabic, History, Natural Science, French and German

By the 1958/59 session, a department of Engineering Technology was started in the Faculty of Applied Science. A three-year diploma course wasinstituted on a sandwich basis,the second year being devoted to practical experience. Students awarded the diploma with sufficiently high marks were admissible, with certain exceptions to the B.Sc. degree course in Applied Science of Newcastle.

FBC moved towards University status and in January 1960, a Royal Charter was granted. The affiliation with the University of Durham continued, and Degrees in Arts, Science, Economic Studies, and Postgraduate Diploma in Theology and Education were awarded by the University of Durham to successful candidates from FBC. The college awarded its own Diploma in Engineering and License in Divinity. As from the 1965/66 session, courses leading to a degree in Civil, Mechanical and Electrical Engineering were started. In the 1966/67 session, the college became a constituent college of the University of Sierra Leone which itself was constituted under the University of Sierra Leone Act 19671. Many of the key officers in Nigeria, The Gambia, Cameroon and to a certain extent Zimbabwe were trained at FourahBayCollege up to the late 1970’s. The current student population at FBC is 3800 with less than 1% foreign students.

Status of the Department Electrical and Electronic Engineering programme

The programme provides a general preparation in engineering for the first two years and specialisation in any of the three disciplines of Civil, Electrical and Electronic, and Mechanical and Maintenance Engineering, starts in the Third Year of the programme. This approach was arrived at after lengthy consultations with the Advisory Committee on Engineering Education2. This body comprises representatives from the top management of the main employers of our students, the University Administration as well as the Sierra Leone Institution of Engineers. This exercise was done at the inception of the Honours degree programme following the cessation of the general degree programme in 1977. It was felt that for a developing country like Sierra Leone early specialisation will not adequately prepare our students for the demands of the profession when they graduate as many of them might be deployed in provincial towns as resident engineers after their pupilage, a posting which will require knowledge in all the traditional branches of engineering. Interestingly the general degree and the honours programmes now run concurrently after it was realised that not all students where endowed with the ability to read at the honours level.

Even at the Third Year and beyond there are still cross cutting modules such as Energy Studies, Power Engineering I and Engineer-in-Society offered by all students in the Department of Electrical and Electronic Engineering, and Mechanical and Maintenance Engineering departments. Students offering Civil Engineering take courses in Geology and Engineering Contracts and Specifications in addition to their specialist or core modules. Plans are far advanced to introduce Architecture and Mining Engineering in the curriculum the latter being in collaboration with the University of Mining and Technology, Tarkwa, Ghana.

It must be noted in passing that all students spend a minimum of six months in an industry as part of their assessed programme. An industrial report and co-supervision of projects constitute an integral component in the cooperation between the industry and the department3.

Team based learning

The approach discussed in this paper of grouping students to achieve certain tasks borrows some aspects of team based learning concepts. Four essential principles of this activity are4:

1)groups must be properly formed and managed,

2)students must be made accountable for their individual and group work,

3)group assignments must promote both learning and team development, and

4)students must have frequent and timely feedback.

The design of the activities to be implemented in a team based environment is also critical to its success as it requires careful planning so as not to be counter-productive. For example if group members realize that they can individually achieve the goals set out in the given assignment then there is no motivation to cooperate and collaborate in this exercise. This is especially true for stronger students who may feel that they have to carry the weaker ones at the disadvantage of their pace of work and perhaps level of achievement5,6.

The method of assessment is also critical to the success of the transformation from a disparate group of students to a cohesive learning team. If only individual grades are given and there is no incentive for group participation, then students may not feel committed to the group and the benefits of this method of instruction can be lost. However if students in a group realise that there is mutual benefit in their working as a team to achieve better results which will impact on their individual grades then there is enough motivation and interest in the group7.

The benefits are namely4:

1. The development of the cognitive skills of students in large classes
2. Weaker students are provided with a safety net through support by team members
3. Interpersonal and team skills are developed
4. Staff members are forced to be fully involved in their courses as the monitoring requirements of this approach are very demanding

Group Tutorials

The introduction of group tutorials was introduced about four years ago following discussions held at the 1stAfrican Regional Conference in Engineering Education (ARCEE) held in Lagos after an enlightening paper presentation8. The author suggested using two methods of obtaining feedback from students that will assist lecturers in assessing the learning process. The first method involved the one-minute write-up by each student of key issues understood from the lecture, immediately the lecture is over. The second was the group activity tutorials. The latter was centred on dividing the class into groups, the size of which will depend on the number of students in the class. Tutorial questions are given to the groups and each group is required to submit one solution of the problem reflecting their joint collaboration. This approach was introduced into two modules in the Fourth Year, students generally find difficult to do well in, i.e. Signal Analysis (EENG 422) and Digital Systems(EENG 421). The Signal Analysis module aims at providing engineering application and understanding of a number of mathematical concepts treated in the previous years in the Mathematics Department, such as Fourier Analysis(i.e. Fourier series and transforms) and their application to spectral analysis, power requirements and bandwidth of transmission of signals. Other new topics such as Convolution and autocorrelation as background material for the modules in Communications, and discrete time systems and z-transforms, as a pre-requisite to concepts in Control Theory are introduced and discussed. The Digital Systems module consists of topics in sequential logic design (both synchronous and asynchronous circuits), logic families and devices. The latter include among others TTLs, CMOS devices, multivibrators, and interface and loading/weighting requirements.

A similar approach has been followed for the Level 5 module Computer Aided Design EENG527. This module introduces students to an iterative procedure of analysing circuits and then uses the Electronic Workbench as a tool for circuit simulation.

Observations

1. The atmosphere during these sessions is at times noisy but vibrant as discussions and arguments progress reflecting the synthesis and distillation of ideas forwarded by members of each team as they grapple with the solution of the problems. Weak students are significantly helped during these sessions and the stronger ones consolidate their understanding of the concepts in trying to assist the weaker ones resulting in a mutually benefiting exercise.
2. In the case of smaller classes, where there may only be two or three groups of say three students, it was observed that one student is selected to write the combined groups’ ideas on the board as they argue and discuss the solution. At the end of the session the solutions are copied and submitted as the group’s efforts.
3. Students’ grades were remarkably improved to the satisfaction of the author, as other methods had been tried with varying but limited successes.
4. Students look forward to these sessions.

This approach also assists the lecturer in having additional assessment of students without the difficulties encountered with large classes with regard to marking many scripts, a situation that could discourage the giving of tests and even assignments. Fewer solutions are required to be marked and students are better informed through interaction with their peers. Of course the solution may have to be formally discussed during a class tutorial especially if there are significant variations in the solutions submitted by the groups which may suggest difficulties encountered in understanding a given concept introduced. A number of colleagues have adopted this approach in the department.

The Computer Aided Design (CAD) module (EENG527) – Theory and Practice

The CAD module is offered at the 5th Year of the degree programme during the 2nd Semester. It covers areas such as General algorithms for analysing circuits, Sensitivity analysis of circuits, Computer graphics and introduction to the Electronic Workbench (EWB) software. This latter component has both theoretical and practical treatments. These two components are also tested during the examinations with a 60% and 40% grade allocations to the components respectively.

The EWB software has a very user-friendly routine for sketching as well as circuit analysis. Its printing facilities are also reasonable and the options to print part lists as well as all instruments, graphs, etc can be quite useful. Within a few minutes of its introduction students can draw demanding circuits and analyse them as well using Bode plots, virtual oscilloscopes, analogue meters, function generators, Logic analysers, and display devices such as LEDs, light bulbs, seven-segment displays, and many others for both analogue and digital circuits. It also has a very useful Help file. It has the Windows look-and-feel with pull-down menus and a library of circuit components and measuring instruments, that are accessible to the user. Indeed it simulates the real laboratory!

The following are some examples of circuits used in the course and students are given group tutorials that are timed as well as practical tests. Using the Bode plot and the Function generator facilities, the circuits are analysed. Component variations can be effected to investigate the effects of changes on the performance of the circuit before building it in the Lab. This is useful in the parameter sensitivity analysis of circuits.

The LowPass Butterworth filter circuit

Figure 1 shows an active 4thorder low pass Butterworth filter that was drawn using the EWB package. In the package the cut-off frequency was found to be 1 kHz. This is confirmed by theoretical calculations using the polynomial expression for this type of filters. The HighPass equivalent is obtained by switching the resistors and capacitors in the input section into the positive terminal of the opamps. The theoretical equations are as follows :

This provides an interesting modification using the EWB confirming the theory. The practical circuit is also experimented on for comparison.

Figure 1. 4th OrderButterworthLowPass Filter. f3dB = 10 kHz

Figure 2. Bode plot display of Filter response

Twin-T adjustable Q-factor Filter circuit

Figure 3 shows a Twin-Tee adjustable Q-factor Bandstop (notch filter) circuit. The Q factor is given by the expression :

Q = fo/(f2-f1)(1)

Where fo is the Notch centre frequency and f1, f2 are the 3 dB frequencies on either sides of the notch frequency. Also the notch frequency is given by

fo = (1/2π){√[(C1+C3)/(C1C2C3R1R3)]}(2)

where R1 =R3=2MΩ, C1=C3=1.32uF, R2=1 MΩ, C2=2.64 uF, R4=10 kΩ variable9.

By adjusting the 10 kΩ variable resistor the Q-factor of the circuit can be varied without affecting the notch frequency.

Figure 3a. An adjustable Q-factor filter

Figure 3b. Notch filter characteristic display

Parallel Up-DOWN counter with switch selection.

Figure 4 shows a parallel UP/DOWN counter with selection facility obtained by the switches labelled ‘UP and ‘DOWN’. The switches must not be HIGH simultaneously. This is an interesting circuit and also treats the operation of the toggle switch in the EWB package