Scatter Graphs

Teachers' Notes

The programme aims to provide interesting and stimulating content that can be used to enhance other classroom work on this topic. It seeks to specifically address the difficulties student encounter in drawing a line of best fit and demonstrates techniques using clear diagrams and graphics. The three main types of correlation (positive, negative and zero) are examined using real-life examples and data that students would normally find difficult to collect for themselves. It is hoped that seeing real-life applications of the topic will motivate and support students to collect and analyse their own data.

The programme could be used to introduce the concept of correlation. It would be equally useful as revision or as consolidation following class work on scatter graphs. It is assumed that students will have some experience of collecting, recording and graphing data. The plotting of points is not carried out in detail. Some students may need to undertake preparatory work on choosing suitable methods of displaying and analysing different types of data. Some students may also benefit from viewing short sections as they progress through stages of the work and then view the entire programme to summarise the main points.

At the end of the section on marathon running times, it may be helpful to pause the tape with the graph in view in order to allow students time to answer the question posed.

At the start of the programme Katie wonders if the number of ice creams sold is related to outside temperature. After viewing the programme, students could investigate a similar question (eg cold drinks sold) by collecting data from the school tuck shop, drinks machine or canteen.