Sampling Methods Comparison

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About This MicroSim

This interactive MicroSim helps students compare different sampling methods and evaluate how each affects the representativeness of research findings.. It supports the learning objectives in Chapter: Human Sciences and History.

How to Use

Use the interactive controls below the drawing area to explore the visualization. Hover over elements for additional information and click to see detailed descriptions.

Iframe Embed Code

You can add this MicroSim to any web page by adding this to your HTML:

<iframe src="https://dmccreary.github.io/theory-of-knowledge/sims/sampling-methods/main.html"
        height="450px"
        width="100%"
        scrolling="no"></iframe>

Lesson Plan

Grade Level

9-12 (High School / IB TOK)

Duration

15-20 minutes

Prerequisites

• Understanding that research conclusions depend on which data is collected
• Basic awareness of what a "representative sample" means
• Familiarity with the concept of bias in knowledge production

Learning Objectives

• Analyze how different sampling methods (random, stratified, convenience, systematic) affect the representativeness of data and the reliability of knowledge claims drawn from that data

Activities

1. Exploration (5 min): Use the sim to sample the population using each of the four methods — random, stratified, convenience, and systematic. After each sample, examine the composition bar chart. Note which methods produce samples that closely mirror the population and which ones show visible skew. Run each method at least twice to observe variability.
2. Guided Practice (10 min): Create a comparison table with four rows (one per method) and three columns: "How it selects," "Strengths," and "Weaknesses." Fill in each cell using what you observed in the sim. Then discuss with a partner: A news headline claims "80% of people support Policy X" based on an online poll. Which sampling method does this most resemble, and why should that affect how we interpret the claim?
3. Assessment (5 min): A hospital wants to study patient satisfaction across all departments. Recommend which sampling method would produce the most representative knowledge and explain why, referencing the composition differences you observed in the sim. Identify one method that would be inappropriate and explain the bias it would introduce.

Assessment

• Accurately describes how at least three sampling methods select participants
• Explains how sampling method choice affects the representativeness and reliability of conclusions
• Applies understanding of sampling bias to evaluate a real-world knowledge claim

Quiz

Test your understanding with this review question.

1. A researcher surveys the first 50 people who walk into a shopping mall on a Tuesday morning. Which sampling method does this represent, and what is its primary limitation?

1. Random sampling — the limitation is that 50 people is too small a sample size.
2. Stratified sampling — the limitation is that the strata may not be equally represented.
3. Convenience sampling — the limitation is that the sample likely over-represents certain demographics (e.g., those who are free on weekday mornings) and under-represents others.
4. Systematic sampling — the limitation is that the interval between selections may coincide with a pattern.

Show Answer

The correct answer is C. Surveying whoever happens to be available at a particular time and place is the defining characteristic of convenience sampling. The primary limitation is selection bias: people at a mall on a Tuesday morning are not representative of the general population, so any knowledge claims based on this sample have limited generalizability.

Concept Tested: Sampling methods and representativeness bias

References

1. International Baccalaureate Organization. Theory of Knowledge Guide. Cardiff: IBO, 2022.
2. Woolman, M. Ways of Knowing: An Introduction to Theory of Knowledge. IBID Press, 2006.