1. Simple random sampling: In this method the samples are drawn in such a way that every unit of the population has equal chance of being included in the sample. Random samples can be obtained by
- Lottery method
- Use of Random numbers.
2. Stratified sampling: In this method the population is divided in to different groups of units called strata, which are homogeneous with respect to a specific character. From each stratum appropriate number of units are randomly selected. This method is called Stratified sampling.
