Laboratory based practical work has been considered as one of the “Sacred Cows” of chemistry teaching for many years. However, attempts to measure the benefits of the laboratory experience to which learners are subjected, with regard to how much learning actually occurs, revealed what can be described as a “pessimistic picture”. Whilst practical work is generally popular with learners and can, to varying degrees of proficiency, engage hand-skills, its ability to generate much active thought or teach theory appears at best questionable. It is my contention (and that of many others) that, for many experiments, the learner’s Working Space is bombarded with information from a variety of different sources which swamps it, leading to an unstable overload state which precludes systematic, intelligent working and causes the learner to seek some more stable (and comfortable) state by a number of devices leading to poor learning. Consequently, it is common to find observers o f laboratory classes, who have their own anecdotes of learners whose behaviour suggests a lack of appreciation or understanding o f what is happening. What may be clearly organised and understood by the teacher (expert) may not be so for the learner (novice), in that information received by the latter may have no apparent structure since adequate previous knowledge is required to make sense of the incoming information. As the important can not be distinguished from the irrelevant, the point of the lesson is lost to the learner. The very common response to this is that the learner follows instructions line by line (blind recipe following) or gives one section of the experiment an inordinate amount of time and attention, whether it warrants it or not and so never finishes the experiment. He may copy nearby learners’ actions or even volunteer to act as the recorder of information for group experiments.

Laboratory based practical work has been considered as one of the “Sacred Cows” of chemistry teaching for many years. However, attempts to measure the benefits of the laboratory experience to which learners are subjected, with regard to how much learning actually occurs, revealed what can be desc...