Identify the sampling method
These exercises ask you to recognize or construct one of four common sample types: random, systematic, stratified, or cluster. First read the situation carefully and look for how the people or items are chosen.
1. Match the description to the method
- Random sample: each member has an equal chance of being chosen.
- Systematic sample: choose every kth item after a starting point.
- Stratified sample: split the population into groups with a shared trait, then sample from each group.
- Cluster sample: split the population into groups, randomly choose some whole groups, and include everyone in those groups.
2. If you must create a sample
- For random, use a random selection from the full list.
- For systematic, find the step size and count forward from the start.
- For stratified, decide how many to take from each subgroup, usually to reflect the subgroup sizes.
- For cluster, choose the group(s) at random and take all members inside.
3. Check your answer
Make sure your final response matches the method described and is simplified clearly. If numbers are involved, confirm the selection pattern is correct and no extra items were added or skipped.