AP Statistics

Advanced Placement Statistics covering data analysis, probability, and statistical inference.

Advanced Topics

Sampling Methods and Experimental Design

Choosing Who and What to Study

Getting good data starts with choosing the right sample and designing fair experiments.

Types of Sampling

  • Simple random sample: Everyone has an equal chance.
  • Stratified sample: Divide the population into groups, then sample from each.
  • Cluster sample: Randomly select entire groups.

Experimental Design

Good experiments control for variables and use random assignment to avoid bias. They often include:

  • Control groups
  • Randomization
  • Replication

Why It Matters

The way you gather data affects what you can conclude. Good design leads to trustworthy results.

Examples

  • A pollster uses a stratified sample to ensure all age groups are represented in a survey.

  • A scientist randomly assigns participants to receive a new medication or a placebo.

In a Nutshell

Learn how to choose samples and design experiments for reliable results.

Key Terms

Randomization
Assigning subjects to groups by chance to avoid bias.
Control group
A group that does not receive the treatment, used for comparison.
Sampling Methods and Experimental Design - AP Statistics Content | Practice Hub