Sampling research methodology
This sampling method is not a fixed or pre-defined selection process which makes it difficult for all elements of a population to have equal opportunities to be included in a sample. Disadvantages include an increased risk of bias, if the chosen clusters are not representative of the population, resulting in an increased sampling error.
However, by selecting friends and acquaintances of subjects already investigated, there is a significant risk of selection bias choosing a large number of people with similar characteristics or views to the initial individual identified.
For example, it will be extremely challenging to survey shelterless people or illegal immigrants.
This is a quick way and easy of choosing participants advantagebut may not provide a representative sample, and could be biased disadvantage.
Random Sampling Random sampling is a type of probability sampling where everyone in the entire target population has an equal chance of being selected.
This method is rarely used in Psychology. For instance, it is easier to contact lots of individuals in a few GP practices than a few individuals in many different GP practices. This may involve specifically targeting hard to reach groups. All members of the selected households clusters are included in the survey.
It gets rid of bias in the population and gives a fair chance to all members to be included in the sample. The selection of the sample largely depicts the understanding and the inference of the researcher.
Types of sampling methods in research
In such cases, using the snowball theory, researchers can track a few of that particular category to interview and results will be derived on that basis. The Purpose of Sampling In psychological research we are interested in learning about large groups of people who all have something in common. In this case, the researcher decides a sample of people from each demographic and then conducts the research on them which gives them an indicative feedback on the behavior of the drug on the population. To encapsulate the whole discussion though, the major differences between probability sampling methods and non-probability sampling methods are as below: Probability Sampling Methods Non-Probability Sampling Methods Definition Probability Sampling is a sampling technique in which sample from a larger population are chosen using a method based on the theory of probability. All the elements are put together in a sequence first where each element has the equal chance of being selected. Use of the Non-Probability Sampling Method There are multiple uses of the non-probability sampling method. This sampling method considers every member of the population and forms samples on the basis of a fixed process. And then the elements are randomly selected from each of these strata. For example, if Square would like to understand the people that could their point-of-sale devices, a survey conducted from a sample of people across US from different industries and socio-economic backgrounds, helps. It is based on convenience.Difference between Probability Sampling and Non-Probability Sampling Methods We have looked at the different types of sampling methods above and their subtypes.