Liven up life in the laboratory

三月 3, 2000

WHAT

Kate Exley takes a practical look at

science and engineering undergraduates' work WHY

Many

students complain that they are fed up with 'following cook books' and want to be the chef HOW.

Practical and laboratory classes are a fact of life for most science and engineering undergraduates. So it is hard to believe that for hundreds of years practical work was demonstrated while students watched.

The laboratory is where students learn "hands-on" skills of how to use equipment and materials correctly and safely. They also learn how to use their initiative, solve problems and design experiments. In their work they will have to make value judgements, analyse data and draw reasonable conclusions.

What do students think about practical classes? First and second-year students spend much of their contact time with academics in practical classes and much of their self-study time writing practical reports.

Sadly, there is often of a distinct lack of enthusiasm for practical classes. The large class sizes frequently help to make the sessions mundane - students refer to "following cook books" and "not really knowing what I am doing or why I am doing it".

However, when students become involved in project work, usually later in their courses, they have a very different reaction. Third-year students undertaking mini-research projects often feel they gain more from this experience than any other element of their courses. They enjoy the project and find it stimulating and exciting.

The questions therefore seem to be: what do projects have that practical classes lack, and what can realistically be achieved in a large first-year practical class?

What follows are a few approaches that some science and engineering courses are using to try to increase the benefits of practical classes in those earlier years of the course.

One feature of project work is that students usually have a considerable say in how their work develops and they therefore feel a greater sense of ownership and responsibility.

In some first and second-year courses academics have tried to build in elements of experimental design and self-determination for the students. The scope of this may well be curtailed because of resource constraints. Two examples are:

In a physiology module at Liverpool University 200 students divide into teams to design, perform and present a series of experiments on the physiology of exercise.

The teams need to book the equipment they require and plan their experiments. Although supported by a tutor, they need to work quite independently most of the time. They present their work by preparing two posters showing the techniques and methods used and the results and conclusions.

On an engineering course at Lancaster, 50 second-year students work in pairs for ten weeks to design, manufacture and test a heat exchanger to a given specification. The students are timetabled for three hours a week and have the help of a tutor and technical assistance in the workshop. The pairs are responsible for planning and executing the practical work within a tight time frame.

A second feature of project work is that the students can make value judgements and begin to evaluate their own work realistically, especially if self-assessment or peer assessment, or both, are encouraged early.

Asking students to assess their own practical reports before they hand them in to be marked by a tutor can dramatically improve the standard of work submitted. When students know the assessment criteria and have guidance on what is expected of them, they have superb tools for learning.

Giving students greater responsibility is highly effective. For example, tell the students at the beginning which skills they need to learn or master by the end of the module/course. Follow on by providing several opportunities for them to practise the required techniques during practical sessions.

In the penultimate class, carry out spot checks and sample assess by, for example, randomly testing each student on one or two of the techniques. Students can re-take any tests in the final class.

If the students work in small project groups or teams they can also benefit enormously from the peer support and help.

Proctoring schemes can build on this approach and also allow students to gain credit for their team spirit and coaching skills. In mechanical engineering at Nottingham Trent University, final-year students act as proctors for a small group of first-year students. They design a gearbox to a given specification and produce a report and layout drawings. They then supervise first-year students who manufacture the gearbox.

The proctor is responsible for planning the manufacture and giving technical advice to their group, who in turn develop the hands-on technical skills required to make the final product.

The proctors are not only assessed on their engineering design but are also given credit for the supervision they give to their group of first-year students.

It is clearly possible to borrow some of the elements of project work that appeal to students and make them work for the large first and second-year classes.

However, the strain of laboratory and practical classes usually hits at assessment time. Many modules and courses require students to write individual reports for each experiment they carry out.

This can represent hours of marking time for the diligent tutor, yet the marks frequently count for a relatively small proportion of the total summative assessment for the course. Tutors need to be creative and think about how they can streamline the assessment

process.

PEPPING UP THE STUDENT PRACTICAL

* List common mistakes and highlight them for individual students.

* Provide a model answer and circle points where a student has made an error.

* Limit the amount students write by encouraging them to be succinct, to the point and structured around questions or headings. An extreme version of this would be to set a multiple-choice questionnaire that could be computer marked.

* Sample assess. For example, a student hands in all eight reports, with a self-assessment sheet for each and the tutor marks two. Alternatively, the student selects which two experiments they would like to write up formally for assessment. The other experiments could be reported in a standard laboratory book that the tutor could ask to see during class time.

* Devise instant assessments during the class itself. For example, students could be asked to produce a quick poster at the end

of their bench showing their experimental results and a demonstrator or tutor could give them feedback.

* In practical classes, limit learning objectives to about three or four.

* Make sure you know how your students will be able to demonstrate the objectives.

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