**SAMPLING**

**TYPES OF SAMPLING**

there are two types of sampling: probability and non-probability

**Simple Random Sampling (SRS):**

It is the basic sampling procedure where each unitin the population gets an equal chance of being included in the sample.

There are two commonly used methods to draw a simple random sample

i) lottery method, and

ii) random numbers selection method.

**Systematic Random Sampling:**

- In this case we select the units in a fixed interval
- This procedure is useful when preparation of sampling frame is difficult or not possible.

**Stratified Random Sampling:**

- This procedure is practiced when the population is not homogeneous but can be divided into various homogeneous groups (called ‘strata’).
- Here we select sub-samples from each stratum and add them together to obtain our desired sample.
- Therefore, the stratified random sampling procedure is a better representative of the population and sampled units reflect the population characteristics more accurately.

**Multistage Sampling:**

- As the name suggests, sampling procedure in this case is divided into two or more stages

**Judgement Sampling**

- It is a non-probability sampling procedure.
- It is also called purposive sampling, where the researcher selects the sample based on his/her judgment.The researcher believes that the selected sample elements are representative of the population.
- The advantage of judgment sampling is that it is low cost, convenient and quick. The disadvantage is that it does not allow direct generalisations to population. The quality of the sample depends upon the judgment of the researcher.

**Quota Sampling: **

- In this procedure the population is divided into groups based on some characteristics such as gender, age, education, religion, income group, etc. A quota of units from each group is determined. The quota may be either roportional or non-proportional to the size of the group in the population
- Quota sampling has the advantage that cost and time involved in selection of units is reduced considerably.

**Snowball Sampling:**

In this procedure you begin by identifying someone who meets the criteria for inclusion in your study