NEET PG High-Yield: Sampling Methods
Sampling is the process of selecting a subset of individuals from a population to estimate characteristics of the whole. Methods are broadly categorized into Probability and Non-probability sampling.
Key Sampling Techniques
| Category | Method | Key Feature |
|---|---|---|
| Probability | Simple Random | Every unit has an equal chance of selection. |
| Probability | Stratified | Population divided into subgroups (strata) based on characteristics. |
| Probability | Cluster | Population is divided into clusters (e.g., villages); used for large populations. |
| Non-Prob | Convenience | Selected based on ease of access. |
High-Yield NEET PG Pearls:
- Systematic Sampling: Selecting every
-th individual from a list. The starting point must be random.
- Multistage Sampling: Used in large health surveys (e.g., NFHS); involves multiple stages of cluster selection.
- Sampling Error: Inversely proportional to the square root of the sample size (
). Larger samples = lower error.
- Bias: Non-probability methods (purposive, snowball, quota) are prone to high selection bias and are generally not used for generalizing results to a population.