Multimedia preparation for first year chemistry and physics laboratories

Abstract

‘Wet’ labs are used because chemistry and physics are experimental sciences. It is vital that students experience real laboratory situations and techniques. It is also important that they learn to work through a whole experimental problem — from aim to conclusion. It is also important, in view of their future employment tasks, that they learn to conduct practical work safely: that they deal with potentially hazardous situations such as handling hot containers, pouring real acid, mopping up spills, and coping with broken glass. It is found that much learning occurs in the laboratory — students comment that a particular point was not understood until they met it “hands-on” in the laboratory. ‘Wet’ labs are high cost facilities. A large cost is incurred in staff time — academic (including co-ordinators and demonstrators) and technical support staff. The laboratory building itself is usually specialised and represents a large capital expenditure. Equipment, including balances, glassware, and instruments, is another cost and the cost of consumables and waste disposal, especially in a chemistry laboratory, is high. The ‘wet’ labs are only available to students for a short time each week (typically 2-3 hours), so it is vital that students make best use of them. To do this, the student needs to come to the lab prepared. Many approaches to laboratory pre-instruction have been tried. In the absence of any formal pre-instruction program, it is found some students do prepare thoroughly (by reading the laboratory manual) while others do not (to the extent of not even knowing which experiment is scheduled). Written exercises are frequently used for laboratory preparation. These may be done hurriedly and in consultation with other students. Demonstrators may give an introduction during the laboratory class, but these have been found to be of variable quality and quantity. In attempting to address these issues we have developed audio-visual based laboratory pre-instruction material — a set of videotapes (physics) and an interactive multimedia CD-ROM (chemistry). One advantage of centrally prepared material is that it gives a uniform starting point for all students undertaking the laboratory. It also may be prepared by experienced teachers, whereas the laboratory staff is often of variable experience and quality (experienced academics; new academics; post-docs; PhD, Masters and Honours students).