How do you tackle controversial issues in science? You could be adversarial and challenge the views of some of your pupils: "climate change is a myth"; "human cloning should be allowed". Perhaps you could suggest that stem-cell research should use artificially created embryos. Whatever the topic, tackling controversy in science can be difficult, but controversy engages children.
For many, science is black and white and provides the "right" answer. Scientists would disagree with this. Nearly all the science we teach has, at one point, been controversial. From unethical experiments (from today's perspective) to simple disagreements about the explanation of a phenomenon, scientists have always been contentious. Even today, controversy dogs many aspects of science from climate change to radiation from mobile phones.
Looking at the history of science can help pupils understand how science deals with controversy and how the results of experiments do not always give a definitive answer.
We often teach that vaccination came from the work of William Jenner, who deliberately infected a boy, James Phipps, with cowpox on 14 May 1796 and then gave him smallpox - a deadly disease. Today Jenner would be struck off the medical register for such an experiment; luckily Phipps survived and so was "born" the process of vaccination.
Except the story is not that simple. Some 80 years earlier, Lady Mary Wortley Montagu observed women similarly injecting their children with small samples of pus from smallpox victims in Constantinople. The children fell ill, but survived and afterwards seemed immune to the full-blown disease. She wrote of this in a letter to friends in London and published an anonymous article on the practice, but her work was not recognised.
So how can we use these stories of controversy in science teaching? We could compare Jenner's with the work on the supposed link between MMR and autism by Andrew Wakefield, who was condemned for taking blood samples from children attending a birthday party.
We could investigate why Lady Mary's observations were not taken seriously by the medical profession - was the letter not seen by the right people? Did doctors have a vested interest in not curing and preventing disease?
Vaccination is a great example of how science works and how scientists will always need to deal with controversy.
James Williams is a lecturer in science education at the school of education and social work, Sussex University.
Visit TES Resources to see a Teachers TV video which investigates the moral and ethical dilemmas of stem-cell therapy.
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