Students are introduced to the experiment and its importance/relevance. They identify variables associated with the experiment and use key words to categorise them. They learn about the types of relationships between variables so they are prepared to make meaningful interpretations of the data.
It is expected that students will have a basic understanding of disease transmission. This lesson would follow on well from 8C Microbes + Disease from the QCA KS3 scheme of work or as part of KS4 Health topics (e.g. AQA Keeping Healthy B1.1.2 How our bodies defend themselves against infectious disease).
- DMD1.1 “Flu: The Numbers” Cards
- DMD1.2 Questions on the Flu Video
- DMD1.3 “The Daily Wail” Newspaper Article
- DMD1.4 “Relationships”
- DMD1.5 “Variables”
Dependent variable, independent variable, continuous variable, discrete variable, control variable, causal, associative, chance, confounding.
- to be able to explain how investigation of this data set can benefit society
- to be able to use key words to describe variables that affect the data
- students can describe the impact flu has on people’s lives and the economy
- student are able identify variables associated with flu transmission and classify them
- students are able to identify confounding variables that exist between other variables
- A number of cards are supplied (DMD1.1 “Flu: The Numbers” Cards) with numbers and corresponding descriptions to match them with. This could stimulate a discussion about the impact flu has on their lives and the lives of the wider community which will help to provide some context to the project.
- These numbers come with a lot of caveats attached and are intended only to stimulate discussion – some will vary wildly from season to season. Further information can be found in the links at the end of this document.
- Following this, you can show a short video clip made by Dr. Rob (our lead scientist) who explains what the project is about and why it’s important.
There is a video clip and further information on the NHS webpage. You could either show the video or if you are based in a computer room allow students to watch the video themselves and look around the site.
In order to help students focus on the task, they should be instructed to look for answers to the following questions in the video clip:
1) How is the virus spread? Where could the virus get into the body?
2) Why won’t antibiotics be prescribed? What kind of drug might be prescribed instead in exceptional circumstances?
3) Who should get a flu jab and why? (a number of possible options)
4) What measures can we use to protect others?
These questions are provided in the DMD1.2 Questions on the Flu Video document. If your school is now running Windows 7, you can “snap” this document to one side of the screen (by dragging the top of the window to the side of the screen) and the clip to the other so students can see both the clip and the questions at the same time.
Relationships between variables:
- Now that students have been reminded about how flu is transmitted, we want to help them to understand the types of variables they will meet in the analysis lesson and the ways in which they are connected.
- A fake news article is supplied (DMD1.3 “The Daily Wail” Newspaper Article) which describes a shock new discovery – that scientists have found a connection between seaside drownings and numbers of people who ate ice cream in the last 24 hours.
- Ask students to criticise this article and suggest why there may in fact be no cause for concern. Introduce to them the idea of a confounding variable (a confounding variable provides an alternative explanation for an effect seen in your dependent – or outcome – variable. Ben Goldacre has written a helpful comment column explaining some of the issues. You may wish to consult your GCSE specification for the exact terminology used by your exam board (e.g. AQA describes two variables that are connected by a confounding variable as “due to association”).
- Give students examples (DMD1.4 “Relationships”) of different relationships. Ask them to discuss the figures and suggest whether there is a causal relationship or whether the variables are only associated by other confounding variables.
- The data on the sheet is fabricated and only intended for example. The first graph hints at the popularity of the sea as a retirement destination. The second graph is based loosely on the IFS and Institute of Education research showing that August babies do less well at school (especially earlier on) as they are nearly a year behind in development compared to other children in the class. The third graph is real but shows nothing more than “where there are people there are phone masts”. The final graph is a nod to “Pastafarianism”.
Complete DMD1.5 “Variables” sheet in pairs. Students should discuss and decide what impact each variable will have on the data and why. There is space to add additional variables. Students could also be encouraged to identify the type of variable (depending on the year group) and to consider which variables they think will have the largest effect on the numbers of people getting ill.
Ask students to pick two variables and identify a confounding variable that could associate them and trick us into thinking there is a causal relationship between them.
And / or ..
Provide students with the statement “flu happens mostly in the winter months – flu must be easier to catch when its cold” and ask them to identify whether they think there is a causal relationship or if there any confounding variables they can identify.
Flu outbreaks can occur at any time of the year (indeed the last swine flu outbreak in 2009 started in the spring/summer) and flu does well in tropical climates. Possible explanations for the seasonal aspect in temperate climates is that people spend more time indoors increasing the chance of transmission. The increased humidity indoors may help the virus survive for longer periods on surfaces too (see the second HPA link below for further information).
Extension / HW
- Pupils could be asked to investigate the flu virus – why do we need immunisations each year?
- Make a model of a flu virus
- Find out how scientists account for confounding variables (high level stuff!)
HPA influenza fact sheet for schools