Misleading graphs for children

Quick answer

Misleading graphs trick people by changing the scale, making bars look bigger or smaller than they really are, or using pictures that don’t match the numbers. You can spot these tricks by checking the numbers on the graph and seeing if they make sense.

Learning outcome

By the end of this page, you will be able to spot when a graph is misleading and explain how it tricks people using different scales, intervals, or picture sizes.

• You can tell if the numbers on a graph are shown fairly.
• You can compare the size of bars or pictures to the actual numbers.
• You can explain why a graph might look different from what it really shows.
• You can make your own fair graph to show the same data.

Why this matters

Graphs help us understand information quickly, but sometimes people use graphs to make things look more dramatic or different than they really are. This is called a "misleading graph". Understanding how to spot these tricks helps you make better decisions. For example, if you see a graph showing how much ice cream your school sold, and one bar is much bigger than the others, you need to check if that bar really shows a lot more or if the graph is making it look like it does.

How it works

There are three main ways graphs can be misleading:

1. Changing the scale: This means the numbers on the graph don’t start at zero or don’t go up evenly. For example, if a graph shows a drop from 10 to 20, it might look like it doubled, but it only went up by 10.
2. Uneven intervals: This is when the numbers on the graph don’t go up by the same amount. For example, if one bar is 5, the next is 10, then 20, the graph makes the jump look huge even if it’s not.
3. Dramatic pictures: Sometimes graphs use pictures or symbols that are bigger or smaller than they should be to make the data look more exciting. For example, if one picture is 4 times bigger than another, but the numbers only show a 2-time difference, the picture is misleading.

Examples you can see

Let’s look at a real example to understand how graphs can be misleading.

Example 1: Changing the scale

Imagine you are comparing how many pets each child in your class has:

If we make a bar graph and start the scale at 4 instead of 0, the bar for Alice (2 pets) will look tiny. But the actual difference between Alice and Diana is 6 pets, so the graph should show this clearly.

Example 2: Uneven intervals

Imagine a graph showing how many books each child read in a month:

If the graph jumps from 0 to 5, then 10, then 20, it makes it look like Grace read 4 times more than Frank, but she only read 2 times more. The intervals are not even, so the graph is misleading.

Example 3: Dramatic pictures

Imagine a graph showing how many football goals each player scored:

If the graph uses pictures where Sarah’s goal is shown as 2 big pictures and Tom’s is shown as 1 small picture, the picture for Sarah looks like she scored 4 times more than Tom, but she only scored 2 times more. The picture size is misleading.

Try it as a mini adventure

Adventure: Graph Detective

You are a detective and your job is to find out if a graph is telling the truth or not. Here’s your mission:

1. Look at a graph with numbers.
2. Check if the scale starts at zero or not.
3. Check if the intervals are even or not.
4. Check if the pictures are the right size for the numbers.
5. Write down what you find and explain if the graph is fair or not.

Here’s a graph to test:

Graph: Number of ice creams sold each day

Monday: 5

Tuesday: 10

Wednesday: 15

Thursday: 20

Friday: 25

Now, imagine the graph starts at 10 instead of 0. What do you notice? Is the graph fair?

Common mistakes

• Mistake: Thinking that a big bar means a big difference in numbers.

  Why it happens: Children often focus on how big the bar looks instead of looking at the numbers.

  Fix: Always check the numbers on the side of the graph to see the actual values.

• Mistake: Not checking if the intervals are even.

  Why it happens: Children may not notice that the numbers go up by different amounts.

  Fix: Count the jump between numbers to make sure they are the same.

• Mistake: Believing that bigger pictures mean bigger numbers.

  Why it happens: Children may not understand that pictures should match the actual numbers.

  Fix: Compare the picture size to the actual numbers to see if they match.

Parent and carer guide

As a parent or carer, you can help your child by:

• Looking at graphs together and asking questions like, “What do you notice about this graph?” or “Is this graph showing the numbers correctly?”
• Encouraging your child to check the numbers on the graph and explain what they see.
• Practicing with real graphs from newspapers, magazines, or online.
• Playing the "Graph Detective" game with your child to make it fun.
• Noticing when your child gets confused and helping them think through the numbers.

Remember, it’s okay if your child makes mistakes. The goal is to help them learn to spot misleading graphs, not to get everything right the first time.

Practice questions

1. Look at a graph that shows the number of books read by students. The scale starts at 5 instead of 0. Is this graph misleading? Why or why not?
2. A graph shows the number of goals scored by players. The intervals go up by 2, then 4, then 8. Is this graph fair? Why or why not?
3. A graph uses pictures to show how many apples each child ate. One child ate 3 apples and is shown with 3 pictures. Another child ate 6 apples and is shown with 6 pictures. Is the graph fair? Why or why not?
4. Which of the following is a sign of a misleading graph? (a) The scale starts at 0, (b) The bars are the same height, (c) The intervals are not even, (d) The graph uses real numbers.
5. How can you check if a graph is fair? (a) By looking at the pictures only, (b) By checking the numbers and intervals, (c) By guessing what the graph means, (d) By asking a friend.)

Answers:

1. Yes, it is misleading because starting at 5 makes the difference between small numbers look bigger.
2. No, it is not fair because uneven intervals make the graph confusing.
3. Yes, it is fair because the pictures match the numbers.
4. (c) The intervals are not even
5. (b) By checking the numbers and intervals

FAQ

What is a misleading graph?

A misleading graph is one that tricks people into thinking something is different from what it really is. It changes the way numbers are shown to make them look more dramatic or different than they actually are.

Why do people make misleading graphs?

People make misleading graphs to make their data look more impressive or to get others to believe something they want them to believe. It can be used in advertising, news, or even school projects.

How can I make a fair graph?

To make a fair graph, start the scale at zero, use even intervals, and make sure the pictures or bars match the actual numbers. Always double-check that your graph shows the data truthfully.

Can all graphs be misleading?

No, not all graphs are misleading. A fair graph shows the information clearly and honestly. The key is to check that the numbers, intervals, and pictures all match up correctly.

What should I look for in a graph to make sure it’s not misleading?

You should check the scale, the intervals, and the size of pictures or bars. If the scale doesn’t start at zero, the intervals are not even, or the pictures are too big or too small, the graph might be misleading.