Types of Probability Sampling

Types of Probability Sampling

Simple Random Sampling Simple random sampling is the easiest form of probability sampling. All the researcher nee ds to do is assure that all the members of the population are included in the list and t hen randomly select the desired number of subjects. Stratified Random Sampling Stratified random sampling is also known as proportional random sampling. This is a probability sampling technique wherein the subjects are initially grouped into different c lassifications such as age, socioeconomic status or gender. Systematic Random Sampling Systematic random sampling can be likened to an ar ithmetic progression wherein the difference between any two co nsecutive numbers is the same. Say for example you are in a clinic and you have 10 0 patients. Cluster Random Sampling Cluster random sampling is done when simple random sampling is almost impossible because of the size of the population. Just imagine doing a simple random sampling when the population in question is the entire population of Asia. Mixed/Multi-Stage Random Sampling This probability sampling technique involves a combination of two or more sampling techniques enumerated above. In most of  the complex researches done in the field or in the lab, it is not suited to use just a single type ty pe of probability sampling. Types of Non-Probability Sampling

Convenience Sampling Convenience sampling is probably the most common of all sampling techniques. With convenience sampling, the samples are selected because they are accessible to the researcher. Subjects are chosen simply because they are easy to recruit. This technique is considered easiest, cheapest and least t ime consuming. Consecutive Sampling Consecutive sampling is very similar to convenience sampling except that it seeks to include ALL accessible acce ssible subjects as part of  the sample. This non-probability sampling technique can be considered as the best of all non-probability samples because it includes all subjects that are available that makes the sample a better representation of the entire population. Quota Sampling Quota sampling is a non-probability sampling technique wherein the researcher ensures equal or proportionate representation of subjects depending on which trait is considered as basis of the quota. Judgmental Sampling Judgmental sampling is more commonly known as purposive sampling. In this type of sampling, subjects are chosen to be part of the sample with a specific purpose in m ind. With judgmental sampling, the researcher believes that some subjects are more fit for the research compared to other individuals. This is the reason why they are purposively chosen as subjects. Snowball Sampling Snowball sampling is usually done when there is a very small population size. In this type of sampling, the researcher asks the initial subject to identify another potential subject who also meets the criteria of the re search. The downside of using a snowball sample is that it is hardly representative of the population.