Distillates - Chemical Education

More effective practical work for A-level chemistry

For most A-level chemistry students, practical work involves 'following a recipe' in what are known as expository activities. This is also the case in many university labs, although in recent years there has been a shift towards a 'problem-based learning' (PBL) approach for at least part of the practical programme in many institutions. The reported benefits of PBL include the development of transferrable skills such as team-working and communication, as well as improved independent learning. In her role as an RSC school teacher fellow, Catherine Smith has developed and evaluated a suite of PBL practical investigations to support A-level chemistry teaching.

A total of 10 activities have been developed, all accompanied by pre-lab exercises and appropriate support materials to help students tackle the problem. Each activity is based on a 'real world' context, and is intended to deepen students' understanding of the laboratory techniques involved. The activities are designed to support different parts of the syllabus so they can be run over the span of a two year course. This article outlines the rationale behind the approach and describes a trial that involved over 100 students in 8 different schools. Pre- and post-activity questionnaires were used to probe the students' views of expository and PBL practical activities, producing some interesting outcomes.

Independent learning is a key concern, especially for students going on to university study. Smith's activities have been designed to give students the opportunity to decode information, use different sources, recognise where help is needed, and the ability to see that making mistakes is a vital ingredient of learning. The evidence documented in the article shows that, for some students at least, these sorts of activities actually do have an impact on students' independence and their ability to think for themselves.

Whenever students are taken out of their comfort zone, there is a risk that they will withdraw due to their fear of the unknown, and this manifested itself during the trial. A sizable minority of students, including some of the most able students, indicated that they were uncomfortable with the PBL activities. However, the overall impact of the new activities was positive for both students and teachers. In particular, the lack of direct instructions was cited by many to be a good thing, with the indication that this led to enhanced understanding. Teachers reported that students were motivated by the activities and that they enjoyed the 'meaty' challenges provided. The fact that they also suggested that they were now planning more open-ended tasks shows the high regard they had for the new approach, which will hopefully give others the confidence to try them in their own classrooms.