Sampling Methods in GCSE Statistics
This page covers various sampling methods essential for GCSE Statistics Edexcel students to understand.
The document begins by explaining that a sample is a selection from an entire population. Sampling is practical, requires less data, and is quicker, easier, and cheaper than surveying an entire population. However, samples can be unrepresentative.
Definition: A census is a survey of the entire population, which is feasible for small populations.
The text then delves into different sampling methods:
- Stratified Sample: Useful when different groups are likely to give different answers.
- Quota Sample: A fixed amount is chosen from each group.
- Systematic Sample: Items are chosen at regular intervals, useful for large populations.
- Cluster Sample: The population is divided into clusters, and groups are chosen at random to sample.
- Opportunity Sample: Also known as convenience sample, it uses people available at a specific time and place.
- Judgement Sample: The researcher uses their own judgement to choose the sample.
- Random Sample: Each member is equally likely to be chosen.
Highlight: A biased sample doesn't represent the population fairly and can be avoided by using random sampling and larger sample sizes.
The page also includes pros and cons for each sampling method, providing a comprehensive overview for students preparing for their GCSE Statistics past papers.
