Forthcoming Conferences

Thirty 14‐15‐year‐old pupils were taught about the effect of temperature and pressure on a gaseous reaction at equilibrium. Two problems were then given to the pupils and a word association test on a small number of carefully chosen stimulus words was administered in the context of the problems. The pupils were finally interviewed about what they had done in the tests. The results of all of the tests were analysed and compared for evidence of perception and strategy.

Various strategies were found to have been used by the pupils: one based on the formally correct perception of Le Chatelier's rule, one based on a perception in which the speed of a reaction is the factor that governs position of equilibrium (this was the major incorrect strategy), one that uses spurious analogies with more familiar factors (such as ‘catalyst') and one that reflects only superficial learning with no evidence of Le Chatelier's principle.

Comparisons with the classroom tests and the interview data revealed that about 60% of the word association test results produced responses that were criterial for the problem‐solving strategies adopted by the pupils, both correct and incorrect. The results show that this type of word association offers a means of unobtrusive, formative testing which, with experience, could be used to anticipate learning problems in science lessons.