Year 9 Science · Unit 4 · Lesson 8

Distorting Data to Mislead

Challenge Worksheet

Name

Date

Class

Learning Goals

Critically analyse a graph or claim to name every distortion technique it uses.
Justify why a distortion changes the message, using correct vocabulary.
Design an honest version of a distorted graph and defend your choices.

Warm Up

Honest vs misleading graph

Both graphs below plot the exact same two values. Study them, then answer the question underneath.

Which graph is misleading, and what single change to its design would make it honest? Write your answer below.

Go Deeper

Evaluate the claim

An advertisement claims...

"Our vitamin tablet makes you 60% healthier! In our trial, the one volunteer who took it every day felt great. The graph below (axis starting at 95) shows our brand crushing the competition, 99 versus 96. Studies that found no effect were not included because they were boring."

(a) Identify at least three separate distortion techniques used in this advertisement, naming each one correctly.

Challenge 3 marks

(b) The ad says "the one volunteer felt great" counts as evidence. Explain why a sample of one person cannot support a claim about everyone, and what a fairer sample would look like.

Challenge 3 marks

(c) Using the four defence checks (axes, sample, source and what is left out), write a short paragraph a careful reader could use to expose this advertisement as misleading.

Challenge 4 marks

Wrap Up

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