equipment forces students to consider the suitability and limitations of equipment. Secondly, opportunities for designing and planning need to be included but in such a way that students are guided through their decision making and self-evaluation. This support was termed ‘scaffolding’ and discussed in Hackling and Garnett (1995) in the context of lower secondary school investigations. However, in senior chemistry, many practicals require specialist skills, techniques and equipment, and so scaffolding needs to be more specific. We propose that it can be provided effectively by a sequence of questions structured to prompt the learner. Lastly, opportunities for teacher feedback and peer assessment can be included to facilitate a critical analysis of planning, thinking and decision making.
Such restructuring yields a task that requires learners to plan, design, evaluate, perform and re-evaluate their work. In addition, it more accurately reflects the collaborative nature of real world investigative science by promoting discussion with peers and teacher feedback. A diagrammatic representation is shown in Figure 3.
An example
Restructuring can be performed on teachers’ favourite practicals by teachers themselves. In the example below, a recipe task is outlined in a structure common to many laboratory manuals. It is followed by a reworking in which the problem (the effect of concentration on rate of reaction) is left closed but the “choosing a method” phase is opened.
This is done by providing:
· a range of equipment;
· a series of questions structured as prompts that act to scaffold students’ decision making, collaborative and reflective processes; and
· teacher feedback and peer assessment.
The restructuring described above is the result of much development over several attempts. We would advise teachers initially to open up only portions of their favourite recipe practicals (as we have) as a stepping stone to a more detailed outcome such as that shown above.
Conclusion
In senior chemistry, learning experiences need to be designed more deliberately to develop processes associated with working scientifically. Practical work can play a key role in developing these processes only if traditional practical tasks are restructured to increase the extent of ‘openness’ by providing:
· a range of equipment to force students to consider the suitability and limitations of equipment;
· opportunities for designing and planning with scaffolding in the form of a sequence of questions structured to prompt the learner; and
· opportunities for teacher feedback and peer assessment to facilitate a critical analysis of planning, thinking and decision making.
Such restructuring yields tasks that require learners to plan, design, evaluate, perform and re-evaluate their work.
Table 1. West Australian and Queensland conceptions
of working scientifically
Western Australia Queensland
Working Scientifically Scientific Processes
Organiser Objective
Planning investigations Devising and designing simple
investigations
Conducting investigations Collecting and organising data
Processing data Processing information
Evaluating investigations Communicating information in
various contexts
Processing data Making simple judgments
