Chemistry is a practical disciple with roots in the experiments of mediaeval alchemists rather than the philosophy of the ancient Greeks. It is therefore not surprising that laboratory work has continued to be seen as an indispensable part of the training of graduate chemists for the past 200 years. However, the importance of practical work within undergraduate courses has started to be questioned. Problems associated with cost, health and safety requirements and the changing nature of employment opportunities for graduate chemists have each been sited, but most critically questions have started to be raised about the learning benefits associated with much practical work and moves to restrict the time allocated to laboratory work are now widespread.
It is, of course, often claimed, that through practical work students can acquire knowledge, advance their understanding of concepts, models and principles and begin to understand what chemists actually do as well as developing appropriate manipulative skills. After all, here in the laboratory we do have active involvement of the learner. However, for meaningful learning, it is the brain, not merely the hands that must be active, and effective thinking is often inhibited, in the laboratory, by information overload of the working memory. Also, all too often, students are furnished with laboratory instructions that amount to little more than cookbook recipes emphasising procedures to collect data or obtain desired products, with little prominence being given to thinking, planning or, often, even to the interpretation of results obtained. Experiments that rely simply on slavishly following a given recipe clearly represent a totally unrealistic portrayal of scientific experimentation. As a result, students often fail to appreciate the relevance of what they are doing, and even why they are doing it and all too often there does not appear to be any convincing evidence that practical work does in fact help students’ understanding of key concepts and theories.
However, one surely can’t become a chemist without a sound appreciation of the role played by experimentation in the practice and development of the discipline. It is, therefore, surely vital that graduate chemists continue to be able to appreciate what can and what cannot be achieved through experimentation. If we believe that practical work must be retained as an essential and central component in the education of chemists we need to ensure that the experience provides more than a simple practice of manipulative skills. However, it is important to accept that no experiment is likely to be able to achieve all the learning outcomes that we might like. Rather, for each experiment, we should identify one or two key learning outcomes that we wish to achieve and select the accompanying assessment accordingly. For example, if our aim is to help students to appreciate natural variations of water hardness levels both the experiment and the accompanying assessment will be different from what would be appropriate if we merely wanted to help students to develop their titration skills.
Further information and discussion can be found in the following references: