Sampling Methods Math Example 1
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Example 1
mediumDescribe four sampling methods: simple random, stratified, cluster, and systematic. Compare their advantages and disadvantages.
Solution
- 1 Simple Random: every member has equal chance; randomly select n from N; advantage: unbiased; disadvantage: difficult/expensive for large populations
- 2 Stratified: divide into subgroups (strata), randomly sample from each; advantage: ensures representation of subgroups; disadvantage: need to know strata boundaries
- 3 Cluster: divide into groups (clusters), randomly select whole clusters; advantage: cheaper (nearby subjects); disadvantage: clusters may be homogeneous (less diverse than random)
- 4 Systematic: select every kth person from ordered list; advantage: easy to implement; disadvantage: if list has periodic pattern, may introduce bias
Answer
Four methods: SRS (purest), stratified (best for subgroups), cluster (cheapest), systematic (easiest).
Sampling method choice depends on the population structure, budget, and research goals. SRS is theoretically ideal but often impractical. Stratified sampling is optimal when subgroup representation is critical. Cluster sampling is used in large geographic studies.
About Sampling Methods
Systematic approaches for selecting a subset of individuals from a population. The main probability methods are: simple random sample (SRS), stratified random sample, cluster sample, and systematic sample. Convenience sampling is a non-probability method that is generally biased.
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