Types of sampling techniques

Non-Probability sampling techniques: This types of sampling techniques in which every unit of the population has not an equal chance of being included in the sample is known as non-probability sampling. The sample are selected on the basis of personal knowledge, opinion and discretion of the sampler. This type of sampling method is also known as non-random sampling. For the opinion surveys, this sampling method is mainly used. There are different types of non-probability sampling methods. They are:

1. Judgement or purposive sampling: In this method, the investigator selects sample items on his own judgement. The choice of selecting sample is nothing to left in chance in this method.
2. Convenience sampling: In this method, the samples are selected on the basis of the convenience of the investigator. It is also known as chunk sampling.
3. Quota sampling: In this method, the population is divided into different groups, known as quota. After doing this, the researcher collects information from quota. Quota sampling is the most systematic and scientific method in comparison with other non-probability sampling method.