Sampling - Type of Sampling for net exam preparation paper 2

                                             Sampling

 Sampling is concerned with the selection of a subset of individuals from within a statistical population to estimate characteristics of the whole population
 

•  Probability sampling is a sampling technique wherein the samples are gathered in a process that gives all the individuals in the population equal chances of being selected.
• Non-probability sampling is a sampling technique where the samples are gathered in a process that does not give all the individuals in the population equal chances of being selected

                                         Type of Probability sampling

Simple Random Sampling 

Simple random sampling is the easiest form of probability sampling. All the researcher needs to do is assure that all the members of the population are included in the list and then randomly select the desired number of subjects.There are a lot of methods to do this.  it can be as easy as using a computer software to do the random selection for you.

 Stratified random sampling 

 Stratified random samplingis also known as proportional random sampling. This is a probability sampling technique wherein the subjects are initially grouped into different classifications such as age, socioeconomic status or gender.Then, the researcher randomly selects the final list of subjects from the different strata. It is important to note that all the strata must have no overlaps.Researchers usually use stratified random sampling if they want to study a particular subgroup within the population.

 Systematic sample

Systematic sampling is a random sampling technique which is frequently chosen by researchers for its simplicity and its periodic quality.The procedure involved in systematic random sampling is very easy and can be done manually.

Cluster sample

Cluster sample the population is also divided into groups, called clusters. But instead of sampling within each cluster, a simple random sample of clusters is selected, and the overall sample consists of all individuals in the clusters that constitute this simple random sample of clusters. For example, if the purpose of the study is to find the average hourly wage of convenience store employees in a city, the researcher might randomly select a sample of convenience stores in the city and find the hourly wages of all employees in each of the stores in the sample.

                               Type of Non- Probability sampling

Convenience sample 

 Convenience sampling is a non-probability sampling technique where subjects are selected because of their convenient accessibility and proximity to the researcher convenience sampling is a non-probability sampling technique where subjects are selected because of their convenient accessibility and proximity to the researcher. In all forms of research, it would be ideal to test the entire population, but in most cases, the population is just too large that it is impossible to include every individual.

Sequential sampling

Sequential sampling  is a non-probability sampling technique wherein the researcher picks a single or a group of subjects in a given time interval, conducts his study, analyzes the results then picks another group of subjects if needed and so on.

Quota sampling 

Quota sampling is a non-probability sampling technique wherein the assembled sample has the same proportions of individuals as the entire population with respect to known characteristics, traits or focused phenomenon.Quota sampling also allows the researchers to observe relationships between subgroups. In some studies, traits of a certain subgroup interact with other traits of another subgroup. In such cases, it is also necessary for the researcher to use this type of sampling technique.

Judgmental sampling

Judgmental sampling is a non-probability sampling technique where the researcher selects units to be sampled based on their knowledge and professional judgment.

This type of sampling technique is also known as purposive sampling and authoritative sampling.
Purposive sampling is used in cases where the specialty of an authority can select a more representative sample that can bring more accurate results than by using other probability sampling techniques. The process involves nothing but purposely handpicking individuals from the population based on the authority's or the researcher's knowledge and judgment.

Snowball sampling

The process of snowball sampling is much like asking your subjects to nominate another person with the same trait as your next subject. The researcher then observes the nominated subjects and continues in the same way until the obtaining sufficient number of subjects