Free IB Maths AA HL lesson: Sampling techniques & bias awareness
A ready-to-teach IB Maths AA HL lesson on Sampling techniques & bias awareness (Unit 4 · Statistics & Probability): editable slides and teacher notes, free; a printable worksheet in 2 levels with answers for school plans. About 55 minutes.
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What's inside
- Slides (PowerPoint, editable) · freeabout 12 slides: do now, objectives, key ideas, a worked example step by step, “your turn”, practice QR code, exit ticket
- Teacher notes (PDF) · freelesson plan with timings, common mistakes, homework links
- Worksheet (PDF) · school plans4 questions, 11 marks: Fluency, Reasoning. Included with school plans and the teacher trial.
- Answers (PDF) · school plansthe answer to every worksheet question, from its mark scheme. Included with school plans and the teacher trial.
Learning objectives
- Populations, samples and sampling techniques
Key ideas on the slides
- A census uses the whole population; a sample uses part of it (cheaper and quicker, but may not represent the population).
- Simple random: every sample of size n is equally likely (random numbers). Systematic: every kth item from a random start.
- Stratified: sample each group in proportion to its size: (group size)/population × sample size. Quota: fill set numbers from each group (not random). Convenience/opportunity: whoever is available.
- Bias is a systematic error that makes a sample unrepresentative; describe it in the context of the question.
By the end of the lesson, students should be able to answer a question like: Why might surveying only library students bias a school-wide homework study?
Key vocabulary
- population: The whole group being studied.
- sample: The part of the population that is studied.
- sampling frame: The list of the population from which a sample is chosen.
- bias: A systematic tendency for results to differ from the true value.
Common mistakes this lesson tackles
- Calling a quota sample random.
- Giving advantages or disadvantages that are not about the context.
- Rounding stratum sizes so they no longer add up to the sample size.
Calculator tips
- Use the random-integer function (RandInt) to choose items for a simple random sample.
Lesson plan
| 0–5 min | Do now: students write down what they remember about Equations of planes; angles & intersections of planes and Reciprocal & inverse trigonometric functions |
| 5–8 min | Share the learning objective and success criteria |
| 8–20 min | Teach: the worked example, step by step; students copy the method |
| 20–25 min | Your turn: 1 mini-whiteboard question; check every board before moving on |
| 25–42 min | Practise: the worksheet (4 questions in 2 levels, with school plans and the teacher trial) or the topic's practice questions online; move up a level after two right in a row |
| 42–47 min | Plenary: 1-question exit ticket; collect it to plan the next lesson |
For students: practise this topic
The worksheet's QR code opens the IB Maths AA HL Unit 4: Presentation of Data practice questions.
What schools get
- Set this lesson as homework, marked by AI against the mark scheme, with every result in your markbook (with a School plan).
- This lesson's worksheet in three levels, with its answers, ready to print.
- Support, Core and Stretch versions and A/B copies of the worksheet from the full question bank, in the worksheet builder.
- Create lesson: this lesson rebuilt for your class's next scheme-of-work lesson, from the full bank.
School licences from €490 a year. Try everything free for 30 days as a teacher: no card.
Questions teachers ask
Is this lesson free?
The slides and the teacher notes are free to download with a free IB Math Revision teacher account (sign in with Google, Microsoft or email); no card. The printable worksheet in three levels and its answers are included with school plans and the free 30-day teacher trial.
Can I edit the slides?
Yes. The slides are an ordinary PowerPoint file: change, add or delete anything. They also open in Google Slides and Keynote. The logo and web address sit on the slide master, so your edits do not move them.
What do students use for homework?
The practice slide's QR code and web address take students to the IB Maths AA HL Unit 4: Presentation of Data practice questions on ibmathrevision.com, where the free questions are open and the full bank comes with a plan.