Teaching and Learning Forum 97 [ Contents ]
Engineering laboratory classes: What purpose and what format?
Robert P. Mun
School of Chemical Engineering
Curtin University of Technology
In any science or engineering course, laboratory classes are used to teach ..... what? What are the purposes of these laboratory classes, and what do they achieve? How should the laboratory classes be structured to achieve these objectives? How can student performance be measured? Is the current format of laboratory classes satisfactory? This paper aims to provoke thought about how laboratory classes should be structured, and perhaps even whether they should exist.
All engineering courses have traditionally had a laboratory class component in their structure. Usually this component is continued at all four undergraduate levels in one form or another, and it forms the bulk of any postgraduate study. This review concentrates on the problems that affect the undergraduate laboratory and its operation, what do the students want and expect from the course, what does the school expect the course to teach, and then how do we deliver these diverse, and often incompatible desires?
Conceptually what the students want is apparent to anyone who talks to the students in an engineering laboratory class, like all undergraduates, their simplest desire is for something that they can pass with the least amount of effort and thought. An informal survey conducted by several of lecturers in the school, and an examination of the "Recommendations and Improvements" section of the student laboratory reports found that the basic desire of the students was for a clear, simple "recipe" which they could follow in the lab, write up thinking only of the questions asked in the work book, preferably which hadn't changed from year to year. To be fair to the students, this will be due to a) their work load; b) the short time of the laboratory classes; and c) the need to score high marks. This last is particularly important in the School of Chemical Engineering, where standardisation is frowned upon, and honours are granted on the basis of marks, not to the top x% of students.
Research into student expectations of laboratory work have been reported several times, Beard et al (1978) reported on Carter and Lee's (1975) study at Salford University, where their results indicated that the student body had a very positive attitude to laboratory work. Students expected the classes to: consolidate learning from the lectures, stimulate independent thought, teach communication skills, to teach experimental skills, to be open ended and easily applicable. The results of this survey are in marked contrast to the informal views expressed above, though they are similar to those reported elsewhere (eg. Miller 1987, Ogborn 1977), though Miller (1987) and Ogborn (1977) both also note that there is a high level of dis-satisfaction with the courses amongst most undergraduates due to the failure of the laboratory classes to meet these objectives. It is likely that this marked contrast in student responses is an artefact of the surveys that have been performed, without the actual survey, it is impossible to be sure, however, it is likely that the students were given surveys with specific questions and asked to select the best response or rate the statement on a scale, and the response form any such survey is then very dependant upon the questions asked. By contrast the informal survey was simply asking students their impressions of the laboratory classes, what they expected and how they thought the classes went. The only common theme between the reported surveys and the informal in-house survey was the student dissatisfaction!
The expectations of university staff are simpler, yet just as difficult to summarise. The guidelines that the staff at the School of Chemical Engineering could agree upon were that the laboratory work should:
These four points form a subset of the 17 possible reasons for including practical work in a science course that were reported by the UTMU (1976) team. Miller (1987) also notes that there are two very important questions that are often overlooked; is their (the objectives of the laboratory course) achievement and essential part of the course? and; are there more effective ways of achieving them? The most interesting point raised in the literature is that there is the belief amongst staff that laboratory work is very important, but surprisingly the operation and design of the laboratory course is usually given to junior members of staff due to the high time requirements involved (Miller 1987, Romiszowski 1981).
- provide concrete examples and demonstration of the subject matter;
- provide experience in the preparation of engineering reports;
- develop practical knowledge and skill with equipment; and
- promote respect for reliable data.
Depending upon the survey that is used, there is a lot of common ground between the staff and the students, or virtually no common ground at all. It is hardly surprising that there is good agreement between the published student surveys and the stated objectives of the staff. As noted above it is likely that the staff were surveyed, a questionnaire designed, and then the students surveyed, so that the results of the student survey would be biased to reflect the results of the initial staff survey.
By contrast the comparison between the informal student survey and the staff objectives leaves a vast gulf. The gulf may best be described by observing that the students wish to be taught, whilst the staff expect the students to learn. The difference being in the manner of teaching and learning. The students, on the whole, want everything made clear to them, with no ambiguity in the objectives or end point of the class, which is entirely understandable given the emphasis that is placed upon achieving high marks. Conversely, the staff expect the students to be independent, to learn how to direct themselves towards a glimpsed but unclear objective, which is a product of the aim of University teaching, to produce life long learners. Clearly the expectations of the staff and students are mutilate exclusive. The problem is how to bring the two groups to a satisfactory compromise.
Currently in the School of Chemical Engineering at Curtin University, laboratory work is performed in nearly all engineering units, and is assessed as part of the units final mark. The advantages of this approach may be summarised as:
The disadvantages of this approach are:
- close direction and design by the lecturer is possible;
- laboratory work is more easily timed to course structure; and
- laboratory work is clearly identified as being associated with a given topic.
An alternative to running individual unit laboratory classes is to group all of a given year levels laboratory work into a single subject. This approach is used at Melbourne University and Monash University, where at each year level there is a unit called "Practical Work". Again this approach has advantages and disadvantages, the advantages are:
- students may have many laboratory classes in a single week;
- the difficulty of designing laboratory work for some units;
- experimental rigs are superficial as they do not overlap into other units; and
- time available for each laboratory class is short.
The disadvantages of this approach are:
- the apparatus can build up into multi-unit operations;
- central direction and co-ordination is achieved;
- more efficient use of supervisory resources; and
- increased time available enables a more open ended experimental design.
Both systems have their merits and work, but what is the best way to achieve the ultimate objective of students who are capable of looking at a problem, suggesting a solution, formulating a plan to investigate the solution, carrying out the program and finally reporting upon the outcome?
- individual lecturers are more distant from the laboratories;
- assumed knowledge levels can be high;
- part-time or repeat students can have difficulties in meeting knowledge requirements; and
- the work load on the organiser is high.
As stated in the previous section, the ultimate objective of the laboratory work in engineering (and presumably science) is to create a graduate who is capable of undertaking research with limited supervision. This is typified by the research project of 4th year engineering students, and the more detailed honours year project of science students. However, most courses very poorly prepare the students for these open ended inquires, as these projects are the first time that the student is given a problem that requires investigation with direction by their supervisor towards an unknown solution, rather than the normal laboratory class, which has a recipe that guides them towards a known solution.
It is not possible just to look at individual units to achieve this objective, rather the entire laboratory program in the course requires an examination. The suggested solution to this problem is to develop a laboratory program that plans to build up the students skills and confidence at conducting "independent" research over the length of the entire course. The students initially expect simple, straight forward laboratory experiments, and need to be guided towards preferring the less structured, more open ended laboratory projects.
To this end, it is suggested that the best solution is a mixture of the two different approaches to laboratory work that were outlined above, the unit approach, and the year level approach. In Chemical Engineering, the entire first year course is taught externally to the School, but those units that do have laboratory work use the unit based approach. First year is not considered in the proposal.
(a) 2nd Year Laboratory Units
It is proposed that these remain unit based, and of limited scope. The purpose of these experiments is to demonstrate to the students the principles of engineering that they are being instructed on. To begin teaching the students how to investigate a problem, it is almost better if the students have not covered the information in the class, however, this situation will never completely arise due to lack of equipment, and the marking of the student reports will have to reflect the differing levels of knowledge with which the students entered the class (Miller 1987).
The laboratory experiments should be re-written to explain what the nature of the problem to be investigated is (eg. the relationship between the rate of heat transfer and the material of construction), but not actually inform them of the precise relationship that they are expected to demonstrate. The students would then be expected to produce a short report at the beginning of the class that demonstrates that they have researched the background to the problem and have some awareness of the expected solution, and would not be able to continue without completing this report. Such research should not require them to go beyond the recommended texts for the bulk of their answer. The operation of the experiment would be given to them in considerable detail, and their would be limited flexibility in the operation of the apparatus. Perhaps only enabling the students to select their own inputs to the system to examine the output.
This procedure would enable the students to learn to refer to existent works to find an expected solution to a problem, and how to articulate the results of their research. The experimental part of the program will familiarise them with various analysis techniques, and how to select sufficient input conditions to verify their proposed solution, the basics of experimental design. This last would require several classes to be conducted on experimental design. With the co-operation of the Statistics Department this could be incorporated in the normal classes, with no extra work required by the students.
(b) 3rd Year Laboratory Units
It is proposed that the 3rd year laboratory unit should become a single unit, rather than each unit having its own laboratory component. For part-time students, a co-requisite would be the completion or current attempting of all of the appropriate units, ie. the laboratory unit must be one of the last units that the student undertakes. The purpose of the course would be to teach the students how to plan an approach to a problem, and how to integrate the ideas from several different units in order to achieve a solution, rather than the solution.
To achieve this will require a redesign of much of the laboratory equipment with the new objectives in mind. The students would be given a problem in very general terms that they must solve (eg. the successful stripping of acetone from an organic solvent and then its final recovery by distillation). To achieve this will obviously take more than one class session, indeed, it is expected that it will take them several sessions. This will enable them to investigate a solution to part of the problem, write an interim report on this aspect, (eg the solvent extraction), conduct further research (eg. the distillation) and then integrate all the steps into a total solution. The solutions will necessarily be different, as different chemical systems can be used, and there are often many solutions to the same problem, especially where control aspects are considered.
As a result of this program, the students will have examined a problem, breaking it into parts and investigating each, and then integrating the parts back into a total solution. Over the course of the laboratory sessions, they will have written several progress reports, a final report, and learned how to consider their solution as part of a whole solution.
An option which is yet to be discussed, is rather than having the one team work through the whole problem over 3-4 sessions, have several teams work on the problem. The groups would break down the problem, and each team would then investigate their component of the problem, and report to the group as a whole. The group would then formulate their final solution, and test it, reporting back to the class with the final solution. The advantage of this approach is that it also introduces the students to team and project management, the dis-advantages are the difficulty of making the team work, and how to get all of the group participating in the final solution. Perhaps each team could perform part of the work in optimising the final solution?
(c) 4th Year Laboratory Units
No change in the current 4th year operation is expected. The students currently undertake an independent research project under a member of staff. Direction is limited to assisting the student to make their own progress, rather than directing them on how to achieve a solution. Most of the projects are of an open ended nature, with the solution being unknown. It is possible that these projects will have to be conducted as small teams in the future due to the increasing size of the 4th year class.
The next stage
Currently no decision to implement the above changes have been made. The members of the staff are considering the proposal for its merit, and difficulty of implementation. The expectation is that some change will need to be made to make the laboratory work more relevant, the perceived problems with any significant change are:
It is expected that the staff will come to an agreement on how to revamp the laboratory element of the course over the break during '96/'97, and that plans for implementation of the changes will be prepared during 1997, ready for implementation in 1998. Once an in principle agreement has been reached, a specific examination of the changes needed in the laboratories can be made, and the final (initial) plan developed.
- increased workload; and
- the difficulty of assuring that the change will achieve the desired outcome.
A proposal on how to conduct laboratory work in an engineering environment to teach students how to conduct independent research has been proposed. This program is still in the discussion stage, and specific plans on how to achieve the stated objectives within a limited budget are yet to be developed.
Beard, R. M., Bligh, D. A. and Harding A. G. (1978). Research into Teaching Methods in Higher Education. 4th Ed. Univ. Surrey.
Carter, Lee (1975). Int J. Elec. Eng. Ed., 12(3) 278-89.
Miller, A. H. (1987). Course Design for University Lecturers. Kogan Page, London.
Ogborn J. (1977). Practical Work in Undergraduate Science. Heinman, London.
Romiszowski, A. J. (1981). Designing Instructional Systems. Kogan Page, London.
UTMU (University Teaching Methods Unit) (1976). Improving Teaching in Higher Education. Univ London, London.
|Please cite as: Mun, R. P. (1997). Engineering laboratory classes: What purpose and what format? In Pospisil, R. and Willcoxson, L. (Eds), Learning Through Teaching, p234-238. Proceedings of the 6th Annual Teaching Learning Forum, Murdoch University, February 1997. Perth: Murdoch University. http://lsn.curtin.edu.au/tlf/tlf1997/mun.html|
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