Using a Visualiser to Enhance Science Teaching

Nick Pollock

Summary

Some important and engaging science demonstrations could be made much better if students could see what was happening more easily. A Visualiser is an excellent tool to help pupils see what is happening. Essentially, a visualiser is a camera, but in a form and with features which optimise it for classroom use. It can be used with or without a PC/Laptop but a projector is needed to get the benefit.

This case study looks at using a visualiser to show clearly the reactions of Group 1 metals with water in a safe manner, yet one which excites the pupils and provides a memorable teaching and learning experience.

Introduction

Curricular Context

Some important and engaging science demonstrations could be made much better if students could see what was happening more easily. A really good example of this is the reaction between group 1 metals and water. Although there are fizzes and flames, the reaction is often very small and difficult for large groups to gather around safely.

Comments by pupils in the lesson included:

“Wow – that’s really cool”
“The picture’s really clear”

“You can actually see the metal going dull again”

“I’m going to stay in my seat. I can see much better here”

Clearly, some of the comments were by pupils who were impressed by the technology itself, which will fade with time but is useful nonetheless. Other pupils were impressed with what they could see. The last quote, unbelievable as it might sound, was from a pupil who was trying to persuade others not to bother trying to see the ‘real’ experiment and to watch the screen.

ICT Approach

A Visualiser is an excellent tool to help pupils see what is happening. Essentially, a visualiser is a camera, but in a form and with features which optimise it for classroom use. It can be used with or without a PC/Laptop but a projector is needed to get the benefit. The device can be used to show pupils the whole process of reacting potassium with water, from highlighting the rapid oxidation on cutting to showing the lilac colour of the flame produced when the hydrogen burns. It is also possible to record still images and short videos.

At first the pupils wanted to see what was happening directly, but they quickly realised they could get a much better view by looking at the projector screen. They were thoroughly engaged by what appeared on the screen as a piece of metal over 1 metre across but was in fact only a few millimetres in size.

The pieces of metal are very small in real life. / This photograph is of the image of potassium being cut projected onto my board. The board is 1.2m high and the image fills it. On the left of the image is a £1 coin for scale
/ The reaction is hard for large groups of pupils to see.

The Visualiser

/ The RM-eye visualiser, showing the moveable camera at the top, the lamp unit in the middle and the controls on the base unit.
A link to details of the RM Visualiser can be found here:
RM Visualiser details
Visualisers range considerably in price but paying more generally gets you more features and better quality images. As a minimum I would suggest a device which has auto-focus and a zoom.

Many teachers reading this will be thinking that they already have some equipment which will do the job just as well; a Flexi-cam or a camcorder and tripod. It is only by using the visualiser in a lesson that the importance of the difference in image quality becomes apparent. The flexi-cam’s image quality is very poor by comparison and it’s manual focus and lack of zoom makes it very fiddly to use. Using a camcorder can be very cumbersome as well as lacking some of the visualiser’s features.

Using the visualiser in a lesson

Class: Year 9; set 3 of 5; mostly level 5 with a few level 6 students.

Lesson: Introduction to the reactivity series

By way of honesty it should be stated that the photographs which accompany this description were taken without a class present. However, they are a replication of what happened in the lesson, though the safety screens have been removed to make it easier to take the pictures.

The glass trough was set up in the classroom so that pupils could see the experiment was actually being carried out in front of them. However, they were asked to stay in their places and to look at the large projector screen.

The white tile for cutting the metals on was placed between the glass trough and the visualiser. This way the camera could be moved from showing the cutting of the metal to the reaction with water just by zooming and changing the angle of the head.

Once the demonstration started the pupils were focussed on the screen. They could see very easily what was happening on a very large image on the front wall of the laboratory.

Setting up the Visualiser

The visualiser is easy to set up. Generally it can just be connected directly to the ceiling-mounted projector in the laboratory. This way it is easy to show the image on the screen quickly. However, the visualiser can also be connected to a PC or laptop with a USB cable. This allows access to a few more features, like taking recording what the visualiser is showing.

The power and the projector connect on the left-hand side. The panel nearest the camera has the USB socket for connecting to a computer and slots for putting memory cards in. This allows snapshots to be saved.

The controls are simple to use and easily accessible.

It takes about 5 minutes to set up as long as you have friendly technicians who will bring all the kit to your laboratory. It can easily be organised while the class are doing a starter activity if there has not been time to do it before the lesson.

A little practice is recommended before using this system in front of a class, but only because working under the camera takes some getting used to. It is very easy to be demonstrating away only to realise that you’ve moved the metal away from the camera’s view!

Other uses

In chemistry, the visualiser has been used to show the rearrangement of atoms with molecular models; useful if you don’t have enough models or you want to show the class something before they have a go. It’s also great for fume cabinet demonstrations, especially if your fume cupboard has grubby windows and lots of frame getting in the way of pupil’s view.

If you’re not a chemist, a visualiser has lots of other potential uses. Anything that is small can be shown on a large screen, from just viewing a small object to demonstrating difficult practical techniques and displaying a close up view of an experiment to make observations easier.

Colleagues have used the visualiser to show microscope slides and ripple tanks. Basically, it’s good for anything where you want to show the detail in something small. The author does not work for any of the manufacturers but he and his colleagues would heartily recommend getting a visualiser.

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