---
title: "DATA 101 · Question the numbers"
publisher: Maestro College (Maestro Open)
lessons: 16
source: https://open.maestrocollege.edu/question-the-numbers
full: https://open.maestrocollege.edu/question-the-numbers/llms-full.txt
---

# Question the numbers (DATA 101)

Why the same data can tell very different stories, and the questions that catch misleading averages, percentages, charts, samples and claims of cause and effect.

Numbers sound certain, but the same data can tell very different stories depending on how it's summarized, charted and collected. This course teaches you to read numbers with confidence and a healthy dose of doubt. You'll learn when an average misleads, how percentages trick people, which charts distort the picture, why correlation isn't causation and how samples go wrong. Then you'll put it to work reading dashboards and asking sharp questions before making a decision. No advanced math is needed.

## Course objectives
- Averages, medians, spread and outliers
- Percentages, percentage points, rates and relative versus absolute change
- Reading charts and spotting misleading ones
- Samples, surveys, correlation, causation and experiments
- Reading dashboards and asking good questions of data

## 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.

## Lessons
### Unit 1: Numbers that summarize
- [Averages, medians and outliers](https://open.maestrocollege.edu/question-the-numbers/averages-medians-and-outliers.md)
- [Percentages and percentage points](https://open.maestrocollege.edu/question-the-numbers/percentages-and-percentage-points.md)
- [Rates, base rates and absolute versus relative change](https://open.maestrocollege.edu/question-the-numbers/rates-base-rates-and-absolute-versus-relative-change.md)
- [Challenge: check the claim](https://open.maestrocollege.edu/question-the-numbers/challenge-check-the-claim.md)

### Unit 2: Reading and judging charts
- [Reading a chart carefully](https://open.maestrocollege.edu/question-the-numbers/reading-a-chart-carefully.md)
- [Charts that mislead](https://open.maestrocollege.edu/question-the-numbers/charts-that-mislead.md)
- [Choosing the right chart](https://open.maestrocollege.edu/question-the-numbers/choosing-the-right-chart.md)
- [Challenge: chart critic](https://open.maestrocollege.edu/question-the-numbers/challenge-chart-critic.md)

### Unit 3: Where data comes from
- [Samples and surveys](https://open.maestrocollege.edu/question-the-numbers/samples-and-surveys.md)
- [Correlation and causation](https://open.maestrocollege.edu/question-the-numbers/correlation-and-causation.md)
- [Experiments and A/B tests](https://open.maestrocollege.edu/question-the-numbers/experiments-and-a-b-tests.md)
- [Challenge: does the evidence hold up?](https://open.maestrocollege.edu/question-the-numbers/challenge-does-the-evidence-hold-up.md)

### Unit 4: Data at work
- [Reading a dashboard](https://open.maestrocollege.edu/question-the-numbers/reading-a-dashboard.md)
- [Asking good questions of data](https://open.maestrocollege.edu/question-the-numbers/asking-good-questions-of-data.md)
- [Making and sharing data-informed decisions](https://open.maestrocollege.edu/question-the-numbers/making-and-sharing-data-informed-decisions.md)
- [Challenge: the skeptical analyst](https://open.maestrocollege.edu/question-the-numbers/challenge-the-skeptical-analyst.md)

## 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.
Start with lesson 1 unless the learner asks for a specific lesson. Keep track of which lesson you are on.

## When a lesson is done
Teach one lesson at a time. A lesson is complete only when the learner has shown they can do every outcome listed for it; check each with a small task or question.
When it is complete:
1. Say clearly: "Lesson N complete: <lesson title>." (use the lesson's number and title).
2. Give a two-line recap of what they learned.
3. Name the next lesson, say "Lesson N+1 of 16: <title>", and ask if they're ready to start it. Start it only when they say yes.
After the last lesson, congratulate them on finishing the course.