** How to demonstrate without being an x **

Public summary: 

Often you may have to demonstrate an experiment with which you have no knowledge about, there are lots of ways to use the experiments to talk about science and experiments without being competent at the subject.

Demonstrating without knowing
Useful information
Kit List: 

Most experiments work well but these are good:
Slug Bubbles
Animal Skulls
Most engineering
Hand Models


So you've been asked to demonstrate something to balance out subjects, cover someone's lunch or fancy a change. Even if you don't know anything about the experiment there's still ways to make it a fun demo.

One of the main things you can talk about is the hypothesis and testing of that hypothesis. Tell them what you're going to do and ask them what they think will happen. Be prepared to provoke and play devil's advocate. If you start with simple things, they'll be able to give you evidence to support what they say. For example, in Slug Bubbles you can ask what will happen to the liquid when the bottom of the tube is removed. They might say it will fall due to gravity, just like they've seen other things fall.

With lots of physics and chemistry experiments this is a great option. For biology you could get them to think about the hypothesis of why this shape is useful (e.g. teeth in animal skulls), and there are often lots of reasons why so everyone can be right.

Try and get discussion flowing and a balance of opinions, emphasis how we can decide which hypothesis is correct and try and test this. You can also talk about cases when it is impossible to test via experiment as it's really difficult. If you test try and reconcile people's intuitions what happened; perhaps the factor they talked about isn't as significant. Physically, you could talk about things having quadratic and cubic relationships and dominating in large limits. Biologically if you're talking about uses then you might have to talk about features compromised between two uses and evolution.

What ways can we have other than experiments to determine something? Dissection, theoretical models, equations, computer simulations. You could think of some examples, what might be the pros and cons of doing these. You can try to link your demo to broader concepts of scientific method and make kids think more generally than in the context of the specific experiment you're demonstrating.

If you have an experiment where it's easy to vary things and test them, get them to do this, or come up with ideas of what to test and how.

Often, though, you'll end up with an experiment you have to demonstrate to the kids with less involvement - Kiwi DNA or some of the more fragile animal skulls are a bit like this. In these cases, try to read the description well - they're actually really helpful! - and think about the questions you would ask if somebody demo-ed it to you. You might want to talk to somebody who knows more about that subject than you do before you demonstrate, or just consult Google between demonstrations if you get stuck. If you're asked something and you have no idea what to say, don't be afraid to admit that you don't know and ask someone else or encourage the kids to look for their own answers when they get home. You can even try to explore any tricky questions with kids and try to work them out together; this can be really interesting for kids since you're getting them to think about something they want to know. They get to lead the demo and you can tell them that this is all part of how real scientists get to the bottom of problems.

In short, the best demos to do when you don't know what you're talking about are the ones for which you can show kids things - it's best if they can get some degree of understanding from experiencing the demo and not listening to you so much. Try to be as subject-specific as you can and pick facts that you think are cool to add to your explanation, but don't be afraid to say you're not sure! Talk more generally about science and the scientific method if you think children will be interested, but try to tailor your demo to the kids in front of you! As long as they think what you're saying/doing is interesting, it really doesn't matter how little or how much you know about your experiment. Happy demonstrating!

Risk Assessment
Date risk assesment last checked: 
Wed, 15/01/2020
Risk assesment checked by: 
Beatrix Huissoon
Date risk assesment double checked: 
Tue, 28/01/2020
Risk assesment double-checked by: 
Polly Hooton
Risk Assessment: 
Hazard Risk Affected Person(s) Likelihood Severity Overall Mitigation Likelihood Severity Overall
Discovering that you hate your own subject One may decide to change subject. All Cambridge Students 4 0 0 Talk to DoS. 4 0 0
Complicated questions Members of public may ask complicated questions you don't know the answer to. Public 3 2 6 Admit you don't know, pick on someone you don't like, say they're an expert and send person to them. Call first aider in case of injury. 3 -1 -3