2. Focus on interpreting data
Scientists need to be able to identify patterns in experimental data. This can be a complex skill and students may face difficulties doing this in exams if they have not practised it beforehand. In Case study 2, the teacher shows her students examples of how data are presented in the media. It is a good idea, as a science teacher, to keep a file of cuttings from newspapers or magazines that you can use with your students. Any story related to science is worth keeping – you never know when it might be useful. Sometimes, newspapers present data in a particular way to make a specific point. Your students need to learn to be critical about what they read or hear. In the main activity, students are given the data in graphical form, but you could show them the graphs and the tables and get them to decide on the best way to display the data.
Case study 2: Explaining patterns in data
Mrs Maduhu had prepared a poster of graphs, charts and tables cut out of newspapers and magazines to show her class that these ways of presenting information are commonly used in many situations in daily life as well as in science, and science examinations. The ways of presenting the data included tables, line graphs and pie charts. She told her students that it was important that they became familiar with reading graphs, charts and tables and looking for patterns in the data so they could understand and explain what these forms of presentation showed. She also showed them how easy it is to emphasise a particular point by changing the scale on a graph.
Mrs Maduhu wrote three tables on the chalk board with data about cardiac output (Resource 4). She asked her students to copy the tables into their science books very carefully, to study the tables for their homework and to look for patterns in the figures.
She also asked them to use their knowledge of respiration to explain each pattern. For students who had time and were interested, she said they could do the same for Table 3. Next lesson, she put the students in groups of four and asked them to share their ideas. They had to choose one pattern they all agreed about, together with its explanation, and present this to the whole class.
Activity 2: Explaining patterns and peer review
Divide the class into groups of three to five students. Hand out a copy of the data on cardiac output and blood distribution to each group (Resource 3). If you do not have access to a copier, use Resource 4 and write the information on the chalkboard. Tell them to write three sentences that describe patterns in the data on a sheet of paper. Give them this example to start them off: ‘The amount of blood going to the brain stays almost the same during exercise.’ Tell them to pass their sheet to the next group, who should decide whether they think each statement is correct. If it is correct they should try to explain the reason for the pattern, using their knowledge of respiration and exercise. They should hand the paper on to a third group for checking. Each group should be asked to read to the class one of the patterns and the explanations written by their neighbours.
You can round off the lesson by reviewing two or three of the key patterns reported and their explanations. You can point out any important patterns that have not been reported on and you can congratulate your class on their developing analytical and interpretative skills.