You're very welcome to Module 3. Having completed the first two modules, we're now going to consider some of the learning theories that apply to laboratory practicals. My name is Claire McDonnell, and I'm one of the course developers. Do you sometimes ask yourself, why do some students seem to be confused about what they are doing during laboratory classes, and perhaps, why are they not able to draw conclusions based on data that has been collected? We would like to present two ideas to you in this module that can help you in these situations. The first idea is Johnstone's triangle of chemistry representations. This shows the gaps that can exist in learners minds between the macro level which is shown on the bottom right, the micro level shown on the bottom left, and the symbolic level shown at the top of the triangle. The second theory is threshold concepts, which encourages laboratory teachers to look more closely into students understanding of basic scientific concepts. Before we look at Johnstone's triangle and threshold concepts though, we'll first consider how learning outcomes for laboratory sessions are formulated. This is important to examine as clearly written learning outcomes ensure that students, academic staff, and laboratory supervisors and demonstrators have a shared understanding of the purpose of a laboratory session. The outcomes also communicate what is expected will be achieved from a practical. To emphasize the importance of clear communication of learning outcomes, we'd like to draw your attention to the intended outcomes for this module which are presented here. We hope that you find Module 3 interesting and useful.