A worksheet is a good way to give instructions of how to carry out practical work safely and effectively. The students can refer to it whenever they are unsure of what to do next and they do not have to waste time copying out the method into their workbook – they can focus on the results and what they mean. However, one of the disadvantages of using worksheets containing detailed instructions is that students can end up following them passively, like a cookery recipe.
In view of this, I have started to develop worksheets for practicals that make extensive use of diagrams or photographs (images can be snipped from instructional videos on YouTube) and the minimum use of words. Furthermore, I include questions about what the students are doing and why they are doing it as discussion points at each stage of the process. Below is an example of one such worksheet that I made for an investigation of chlorophyll using paper chromatography.