Author note — to cover

Cover systematic sampling (every nth from a list) and opportunity or convenience sampling; questions name the method used and identify who gets missed. Naming and critiquing only, no calculations. Stratified and quota sampling are out, beyond 9-1 GCSE; stratified reappears at A level. Bias itself is the sibling page. Both tiers. (S1)

Introduction

—coming soon—

Practice and continue

Practice

Non-random sampling

Systematic and opportunity sampling, and the groups each one quietly misses.

Next lesson

Bias in sampling

How time, place and selection method favour one group, and whom a survey misses.