Don't let it blow up in your face

Teaching students in the lab is fraught with danger. Getting to know the technician can safeguard against hitches while creating a social atmosphere gets sessions going with a bang, says Harriet Swain

You've booked the room. You've persuaded the students to turn up. You've signed the relevant forms regarding the incredibly expensive and complicated piece of equipment you want to use, and have a technician on hand to help if you forget what it does. The only thing you have to do now is to start teaching your laboratory class. How do you go about it?

Make sure you've already started talking is the advice of Jo Corke, a staff development consultant in science and engineering. She says you should try to speak to whoever designed the course you are teaching and try to make a friend of the technician, who will know more about the lab than anyone else. In its tips for laboratory demonstrators, which are available online, the Oxford Centre for Staff Development stresses the importance of talking to everyone involved in the class, including the person who ran it last time, as well as ensuring you have obtained lab sheets, protocols, outlines, question sheets and answers, and safety guides.

One of the tips is to make a checklist of the equipment and skills you will need for each lab class, from course documents and equipment manuals to protective clothing and equipment. Another tip is to ask yourself whether you know how to use the equipment, whether you know the safety drills, the underlying theory and the main problems students experienced the previous year.

All this should help you to clarify what the lab class is for and ensure that everyone in the teaching team agrees with you. Reg Jordan, dean of undergraduate studies at the faculty of medical sciences, Newcastle University, says the first step is to decide what skills you want students to have gained before they graduate and ensure that the practical classes help them to acquire those skills. "We are relating what they learn practically to professional skills," he says.

The best way to give students this kind of competence, according to Frank Harrison, senior lecturer in educational development at Imperial College London, is to offer guidance rather than to do the experiment for them.

"Students learn best by active learning - thinking about what is happening, about what mistakes they have made," he says.

Assessment is therefore something that should be considered early on, Harrison says. He says the difficulty of discussing skills rather than knowledge means that you need to have a tight marking schedule to ensure that the assessment is reliable and consistent.

Caroline Baillie, author of a guide on teaching laboratory classes in materials science, says that assessment tasks for which students "write up" an experiment, without giving further guidance, encourage them simply to reproduce what they did (or what the previous year's students did).

Students should be encouraged to reflect on why they did the experiment and what they got out of it.

She suggests showing reports written by previous students, offering feedback on draft reports, or involving students in developing suitable criteria for assessment and critiquing how these are met.

Using a range of assessments encourages students to take lab work seriously and to understand what can be assessed, as well as helping to counter gender or cultural influences that may make one type of assessment more accessible to a particular group, she says.

Baillie warns that fudging laboratory assessments is common, especially in exercises where students are expected to give little personal input into the work. She advises avoiding these kinds of experiments in favour of those that are relevant to future course work or careers and in which students have more sense of ownership.

She suggests reducing the emphasis on right answers in favour of discussion, allowing students to choose which exercises should be assessed according to, for example, which they found most challenging or to which they made the greatest personal contribution, and making sure that assessments are based on topics that differ from those of previous years.

A logbook, in which students record the day's results in a permanent form, is useful, she says, as is asking students to compare their results with those of other students.

Finally, she advises limiting the range of goals for laboratory exercises.

If students are overburdened, they may be more likely to cheat.

Corke agrees that you have to be realistic about what can be achieved. New lecturers have a list of things students should be able to do and think they have to address all of them in every lab session, she says. It is better to address just two or three of them properly. And she warns against trying to force a lab session that used to last three hours into the two hours more common now.

"It is worth telling students that these labs are a kernel about which they need to develop some ideas of their own," she says. "They aren't everything they need to know."

She also advises making lab classes fun - allowing people to speak when working in groups, for example, and conveying enthusiasm and excitement in the work of being a scientist.

"Make the lab a social as well as an intellectual experience," she says.

"Remember that students have feelings and a social life and that, although the lab may be the most important thing in your life, it may not be in theirs."

Further information:

Effective Laboratory Demonstrating - video available from Richard Young, Quality and Standards Unit, Newcastle University, Newcastle NE1 7RY.

Teaching in Laboratories , Boud, D, Dunn, J and Hegarty-Hazel, E (1989), Kogan Page.

"Teaching Materials Laboratory Classes", Caroline Baillie and Elizabeth Hazel, www.materials.ac.uk/guides/labclasses.asp

Top tips

Encourage a sense of ownership among students by favouring investigations and projects over controlled experiments

Hone your technical skills

Don't try to do too much

Make the lab a sociable place to be

Keep your eye out for technical developments that will improve learning and may make your life easier