Year 9 Science · Unit 4 · Lesson 8

Distorting Data to Mislead

Foundation Worksheet

Name

Date

Class

Learning Goals

Recognise common ways data can be distorted in graphs and statistics.
Explain why accurate numbers can still be shown in a misleading way.
Use key vocabulary: distort, truncated axis, cherry-picking, mean, median.

Warm Up

Sort it!

Write each item from the pool into the correct box. Decide whether each one is a way data is honestly shown, or a way data is distorted to mislead.

Y-axis starts above zero to stretch a small gap Y-axis starts at zero Showing only the results that fit your conclusion Showing the full range of years "Cases up 50%" without saying 50% of what Reporting the sample size clearly Using the mean when one huge outlier distorts it Using the median when there are outliers Cutting the graph to one favourable window Noting who paid for the study

Honest

Distorted / Misleading

Your Turn

Fill the gap

Choose the correct word from the word bank to complete each sentence. Two words will not be used.

distort truncated cherry-picking mean median outlier sample correlation colour

To data means to present it in a way that pushes a viewpoint rather than the honest picture. A graph with a axis does not start at zero, so small differences look much larger. Showing only the results that fit a conclusion, while hiding the rest, is called . The is the arithmetic average, and one extreme value called an can pull it far from a typical value. The is the middle value and is often fairer when extreme values are present. When two things rise together it shows a , which on its own does not prove one causes the other.

Show What You Know

1. Explain how a bar chart can make two almost-equal values, 96 and 98, look very different, even though both numbers are correct.

Recall 2 marks

2. A headline reads "Cases up 50%!" The cases rose from 2 to 3. In your own words, explain why this headline is misleading.

Recall 2 marks

Wrap Up

In one sentence, what was the main idea of this lesson?