‘Student’ demonstrations, but the good kind

Every year I look forward to teaching, and the highlight for me is teaching in one of the largest classes that my organisation offers – introductory psychology. While I enjoy all of that experience, there are some parts I really look forward to: In-class demonstrations. I’m sure I’m not alone in this, and it may seem odd to even write about the utility of demonstrations, but that is exactly what follows. Specifically I’d like to ask the question of whether in-class demonstrations really are helpful, when are they helpful, and reflect on some of my own experiences.

In common with many places outside of New Zealand, most local universities (though not all disciplines) make reference to laboratory demonstrators as important contributors to, and supervisors of, learning. But what do demonstrators do? At the very least, the implication is that they ‘demonstrate’ something. Courses of study at all levels, typically but not exclusively sciences, offer demonstrations because of the belief that they encourage learners to actively engage with their subject by seeing and maybe participating in something that helps consolidate or illustrate important class content.

But is this really the case? I had always assumed this to be so, until I actually looked for evidence in support of my assumption. To cut the story short, the answer is reassuringly 'yes, but not always'.

Demonstrations are tools, and like any tool they can be used well or badly and sometimes not with the desired consequence. We can be confident in our intuition that showing learners something analogous to the things we are trying to explain is a potentially useful thing to do.

A first question is this – when do we use demonstrations? The answer, usually, is when we are seeking to illustrate something novel, and demonstrations are not the only way to do this. We might also use analogies and metaphors under similar circumstances. Research by Critical thinking specialist Diane Halpern and her colleagues has backed up our intuition that this is useful by showing experimentally that analogies (describing parallels with more familiar things that are similar, but not too similar, to the thing we’re trying to illustrate) assist understanding, recall and encourage critical thinking better than more distant analogies.

But back to demonstrations. In my large classes I employ a range of exercises, large-scale experiments, and demonstrations hopefully to hold student attention, and illustrate lecture material. Maybe one, every second meeting. Numerous authorities advocate that in-class demonstrations serve multiple positive functions. These include attracting and holding attention when they might otherwise be drifting and creating active learning experiences that bring to life demonstrated principles, making them particularly memorable. In-class demonstrations can serve as course highlights that students and teachers can look forward to and enjoy.

Scientist and educationalist, Eric Mazur and his colleagues, operating in the area of physics and natural science teaching, have argued that demonstrations work best when learners are given a chance to predict the outcome and explain their rationale, and have the opportunity to reflect on what actually happened and why. In fact, without these two key opportunities, demonstrations run the risk of negative consequences. Specifically, come assessment time learners show a tendency to ‘retro-fit’ their memory of the demonstration to whatever they might have anticipated as the outcome before participation. If there’s one thing most people accept (and particularly memory researchers) it is that our memories are fallible and malleable!

As well as providing opportunities to predict and reflect on demonstrations, my own experience suggests that over-use should be avoided too. If learners expect frequent demonstrations their impact can be lessened. Variation is also important, and relevance is essential. Sometimes coming up with a good demonstration is genuinely tricky, and half-hearted or not-quite-right attempts can damage potential understanding.

Inspiration for new demonstrations has come from various places – sometimes from the work of other people in my area (for example, a mind-reading exercise described by Philip Zimbardo that involves asking students to think of limited number sequences and then guess a name based on them, to encourage critical thinking and introduce theories and hypotheses), from people in other disciplines altogether (giving students True/False cards to get quick feedback in a clicker-free class), and sometimes quite out of the blue (using a set of disc-sorting boxes abandoned in an office I inherited to illustrate group versus individual task performance).

One thing all these examples or most new demonstrations have in common, is risk. I have been almost paralysed with anxiety in the lead-up to a new demonstration, to the point that I’ve been lucky I could do it at all. What if it doesn’t work? The answer is that if the demonstration was any good in the first place, it often still works for the purpose of teaching and learning (though one’s nerves might still be shot). Be prepared for it to go wrong (I have an 85% hit rate with mind-reading), and develop contingencies. If it goes wrong, learners can still learn from the description of what should have happened, and speculate on why it didn’t happen as planned.

The psychological illusionist Derren Brown (and probably most other illusionists) suggests that one of the keys to a good magic trick is that at the key moment of the illusion, the presenter is relaxed. So stick with a promising demonstration even if it fails the first time. My experience is that sometimes the best ones don’t turn out as planned initially, but like many other parts of successful teaching and learning they get better with practice. While these messages will be utterly familiar to most, thanks to the likes of Halpern and Mazur we can be confident that our intuition about the utility of demonstrations is generally well-founded.

Marc Wilson is a member of the Ako Aotearoa Academy of Tertiary Teaching Excellence

To read Marc's teaching profile click here

Originally published in the Education Review 15th May 2009.