Viewpoint

If the Cap Fits...

It would seem reasonable to expect school science education to mirror `real' science in its practices. This view forms an undercurrent throughout John Packer's article [School Cert Non-Science, February]. But the parallel breaks down when considering the function and nature of experiments in the two pursuits.

To the professional scientist, an experiment is designed to further knowledge in a specialist field. As results are not known with certainty prior to the exercise, an experiment which `doesn't work' is frequently as informative as one that does.

In science education, however, a good experiment is one in which the results are well known beforehand, and which clearly illustrates an established scientific principle. An experiment that `doesn't work' does not achieve this aim and creates confusion in the pupils.

Science education has traditionally used experiments as verifications of pre-taught theory, sometimes called the classical-demonstrative approach. It can't be called science in the methodological sense of the word, but it achieves an educational objective -- the manifestation of scientific processes in a hands-on laboratory setting.

This approach came under heavy criticism because it was so divorced from those of real science. Pupils were not being encouraged to think scientifically, to adopt problem-solving mental processes involving hypothesis formulation and experimental design. The discovery-learning approach was proposed to correct these deficiencies. Pupils would discover scientific principles for themselves by applying scientific investigation methods.

The pure discovery approach makes the unjustified assumption that pupils have the intellectual ability to mimic the modus operandi of real science. Most children have neither the prerequisite knowledge to be able to ask the right questions, nor the laboratory skills to be able to tackle a practical problem in a scientific way.

Pure discovery becomes pure frustration. The more intellectually gifted students often see discovery for what it is -- essentially a con-job. It is an attempt to make pupils retrace well worn steps, a job more easily accomplished by consulting a reference book.

The primary aim of secondary science education is to produce a general public with a grasp of scientific principles and an awareness of scientific methodology. Given this mandate, it is legitimate to `cheat' a little by engaging pupils in experiments that are not genuinely experimental. But mid-secondary science education should involve some scientific reasoning and the excitement of scientific discovery.

This can be achieved via guided discovery, which recognises pupils' limitations, and uses introductory theory to generate problems amenable to laboratory investigation. This is carried out following prescribed instructions, with a degree of pupil input. The results are not known with precision by the pupils prior to carrying out the experiment, which introduces an element of genuine personal discovery.

Guided discovery is still not science as scientists envisage it. But it is a legitimate way to satisfy the objectives of secondary science education.

Barend Vlaardingerbroek is a science education lecturer at PNG University