Problem-solving at the bench;Platform

15th March 1996 at 00:00
Colin Wood says that science must distinguish between learning and assessment

Science has a justifiable place in the curriculum as one of the modes by which we can address questions to our environment and get answers from objects which cannot talk. The essence of this inquiry is experiment, where questions are framed in such a way as to yield an answer which is often unique. Experiment is therefore an essential part of science teaching if it is not to degenerate into absorbing predigested and little understood facts as its principal activity. Science teachers are fortunate in that they have a range of instructional modes, such as straight talk, discussion, textbook, interactive information technology as well as practical work itself. These can give variety to the work and provide learning means to fit the different learning styles of most pupils. However, it does not follow that every teaching mode should be assessed; rather it is the total learning experience that has to be assessed.

It is necessary to distinguish clearly between a learning mode and an assessable element. If the skills of chemistry (or science) practical work were life skills of any permanent importance, then examination of them is necessary; titration, the ability to run a chromatogram and so on do not fall into this category.

The fundamental purpose of practical work is to bring reality to bear on beliefs, and even in this it is not infallible because beliefs can control the questions asked. Practical work must be woven into the whole fabric of teaching in such a way that a lesson reaches a point where the class does not know the "answer" to something. The teachers and the pupils together set up an experiment to settle a point. The pupils have a hand in the design (by discussion) and in the interpretation of the results.

For example, we might overhear a class discussion. "How could we get some pure oxygen in order to find out how it behaves" "Where could we get some?" "Oxides, -ate compounds etc." "How can we get it out?" "Heat?" Allocate jobs on oxides, -ates etc and find out. Result - limited success, but is there a pattern? And so on.

When pupils have met this way of addressing questions to inanimate objects, they will gain enough skills to tackle some things on their own and here comes the space for more open-ended projects appropriate to their knowledge (so that they can frame questions) and experience of how to go about things (control variables, for instance). These need not be examined but pupils should have this experience as part of their science entitlement. Most of the factual material fades with time, but how to go about tackling a problem systematically is a life skill. This should be reinforced across the curriculum in all the sciences as well as in other disciplines. Pupils must be made aware that it is a powerful skill, but is not always appropriate to all situations, as there are other modes of knowing, deciding and problem-solving.

So there is no necessity for assessment of practical skills in science; what is important is to inculcate a practical approach to problem-solving which should be woven into all the teaching of the subject - the constant appeal to the bench.

By its very nature, assessment of practical problem-solving skills kills spontaneity and brings us to the current situation where pupils are so accustomed to feeling that they have to "get the right answer" that they are misled into thinking that there must be a unique answer to every problem in science. We are reinforcing within our pupils a closed "all is known" view of science; a discipline where any personal contribution is neither necessary nor desirable.

Such a parody of science must dissuade original and innovative thinkers from studying science to a high level; and yet these are the very people who have the personal characteristics to go on and be at the leading edge of science and engineering research and development. Commenting on the Higher Still proposals, the Royal Society of Chemistry noted: "Standard grade practical assessment leaves much to be desired; it is a caricature of what practical work should be about. It is a narrowing experience which neither excites our pupils nor encourages them to use initiative or resourcefulness."

If the problem lies with the assessment rather than with the activity itself, then the assessment should go and the activity should be engineered to give a beneficial learning experience. However, concern has been expressed that if practical work was not assessed by the Scottish Examination Board less would be done. The temptation would be for schools to spend practical time on the other elements in order to get best examination results.

There are two types of practical work and each should be assessed in its own way. The first is practical assessment, as in the Higher grade chemistry syllabus with its prescribed practical activities which are specifically examined in the written examination. Many of these would quite properly be of the "recipe-following" type. They would be assessed in the written examination and it would not be necessary to assess them internally.

The second type involves practical problem-solving, an activity which should be an integral part of the course, just as it is an integral part of our subject. Teachers who have used problems like those from Robert Hadden's book Problem Solving at the Bench (published by the Centre for Science Education, Glasgow University) have been pleasantly surprised at their motivating affect on pupils of all abilities. They allow pupils to be inventive and encourage them to think divergently. They allow them to see chemistry as an exciting activity where they can put to good use the knowledge and experience learnt in their course.

There is no doubt that practical problem-solving activities are in themselves successful and are enjoyed by pupils. However, in the view of many teachers assessment kills spontaneity and enjoyment and encourages an inappropriate approach. To prevent this the school could assess each pupil's group of practical problem-solving activities (not each one individually) on a passfail basis. This assessment would ensure that a set minimum number of activities had been carried out: it would not set out to assess the quality of the work. The vast majority of pupils would pass. (This is common practice in universities, where a certificate is required before a student is allowed to sit the corresponding degree examination.) Research published last year on the scoring of such practical problems could form the basis of pupil assessment, should the SEB feel this necessary.

The Royal Society of Chemistry represents chemists at all levels in education and in industry. The Education Division has particular responsibility for education at all levels; its Scottish committee is widely representative of practising chemists in Scotland and has taken the initiative in promoting advances in chemical education in Scotland for more than 20 years. The opinions expressed here are based upon the Scottish Education Division's recent submissions to the Scottish Examination Board on the assessment of practical abilities and to the Scottish CCC on Higher Still. They do not necessarily represent official RSC policy. Correspondence should be directed to Colin Wood, honorary secretary, 10 Melfort Drive, Stirling FK7 0BD.

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