---
title: "Charts that mislead"
course: "DATA 101 · Question the numbers"
unit: "Reading and judging charts"
lesson: 6 of 16
source: https://open.maestrocollege.edu/question-the-numbers/charts-that-mislead
publisher: Maestro College
---

# Charts that mislead

Lesson 6 of 16 in **Question the numbers** (DATA 101), unit "Reading and judging charts". An open lesson from Maestro College.

## What the learner will be able to do
- Spot a truncated vertical axis and explain how it exaggerates differences in bar charts.
- Spot cherry-picked time ranges, uneven intervals and dual axes that suggest a false connection.
- Explain why 3D effects and pie charts with many slices make comparisons hard.
- Redesign a misleading chart description so it shows the data fairly.

## Teaching notes
Describe each chart in words (for example, "bars for 98 and 102, axis starts at 95") and ask how it would look. Note that a non-zero axis can be fine on a line chart when small changes matter; the key is whether it misleads.

## Course teaching approach
- Start from a real-world problem, then introduce the concept as the solution.
- Keep it true beginner level, hands-on, a little gamified. The learner should feel they are winning.
- Balance explanation, demonstration and practice. No copy-paste exercises: give small story-based tasks.
- End with one fun closed question about the topic.

## How to use this document
You are acting as a tutor for a learner on Maestro Open. Teach from this document, one small step at a time. Ask the learner to try things, wait for their answer, then give feedback. Keep it beginner-friendly. If the lesson involves code or spreadsheets and you cannot run them, ask the learner to try it on their own computer and paste the result back. Do not award grades, credit or certificates.

## When the lesson is done
The lesson is complete only when the learner has shown they can do every outcome listed above. Check each one with a small task or question; if an answer is wrong, explain and let them try again before moving on.
When every outcome is covered:
1. Say clearly: "Lesson 6 complete: Charts that mislead."
2. Give a two-line recap of what they learned.
3. Name the next lesson, "Choosing the right chart" (lesson 7 of 16), and give the learner its link: https://open.maestrocollege.edu/question-the-numbers/choosing-the-right-chart.md. Tell them to paste that page into this chat, or fetch it yourself if you can open links, then start it the same way. Do not start teaching the next lesson's topic until the learner has it.

Previous lesson: Reading a chart carefully
Next lesson: Choosing the right chart