Cool water

6th January 2006 at 00:00
Nicola Pollock on how enthusiasm in a competition has made science all the rage

Six months ago an entry form for a science competition appeared in my pigeonhole. This autumn, I found myself, hands shaking with nerves, at the Royal Institution.

And all because of Express Yourself, an event run by Sheffield Hallam University. Pupils conduct research and experiments on a chosen topic. They then prepare a talk and a poster to communicate their findings to other pupils, teachers and scientists at a regional conference. They are judged on how interesting their project is, and how effectively they communicate.

Winners enjoy an all-expenses paid trip to the London final.

This year's team were finalists developing a kit for farmers to test run-off on their farms for pollutants. They contacted a water-testing laboratory to find out methods for testing for pollutants and learnt that calculating the biological oxygen demand (BOD) was a viable way of finding out how polluted a water sample is.

The BOD is a measure of the amount of oxygen removed from a sample of water in a given time. If a sample of water contains a lot of organic matter, such as nitrates, it will support a large number of bacteria. The more bacteria, the more oxygen they will remove from the water during respiration, resulting in a higher BOD.

Pupils trialled different methods and settled on the Winkler method, which involved carrying out a titration on samples collected from farms. They made up a kit with all the required chemicals and safety equipment for farmers. They produced a simple instruction leaflet with a systematic method and safety measures. Also included was a calibration curve with indicators of how safe or harmful the water was. Harmful water must be stored in special tanks or the farmer may be fined.

The pupils researched the Nitrates Directive, a new law being introduced in Northern Ireland in 2007 which will affect all farmers; what nitrates do to the environment; how nitrates can be tested for in water samples; what all the chemicals in the experiments were used for.

They allocated responsibilities: who would conduct the research; who speak to farmers about the nitrates law; who to check and record results of the experiments everyday. They also conducted experiments using the colorimeter and method. They recorded all information in a group log book.

Pupils have developed confidence in their ability to communicate with large groups of people. They have become familiar with titrations, eutrophication and balancing environmental concerns and economic viability. In class, their scientific reasoning has blossomed; they have a better understanding of scientific methods and see investigations as exciting. Now, more pupils want to become involved in Express Yourself, the science club has more members than it can hold and science is "cool".

Nicola Pollock teaches science at Ballycastle high school, Northern IrelandFor the Express Yourself;


Make it relevant to pupils' lives

Keep the science behind the topic simple. Bamboozling them with technical terms and complicated experiments can be off-putting.

Use humour.

Choose a project with a clear aim and keep pupils on target. Some project titles are too vague and would involve an unrealistic amount of work.

Prepare a project for competition or display

Have a well-organised, clear timetable. Set short-term goals, allow for time-consuming experiments and practise talks.

Keep a log book to record all research, results, ideas and sources of information.

Give pupils ownership of the project; they should do background research themselves via the internet, books or journals. They should organise how they share their findings with others

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