- MemberDecember 21, 2021 at 9:00 pm
In research, researchers need data to evaluate for the conclusion of the research. In order to have the data, the researcher needs to do sampling. Sampling is a procedure of choosing individuals or a set of the population to make statistical assumptions from the whole population that the researcher intends to carry out the research. Researchers use different sampling methods in research to avoid data collection from the entire intended population. There are two types of sampling in market research, probability sampling whereby the researcher will set selection criteria and choose the individuals of a population randomly and non-probability sampling, whereby the researcher will not fix or predefine the selection process and randomly chooses the individuals from the intended population. Whichever the research chooses as a sampling method, must be clearly defined in the research methodology.
The Sampling frame is the list of the entire targeted population of the research. For Example, you are carrying out research at XYZ Sdn Bhd in Bukit Gantang. The total number of employees is 2000 people. Therefore, my sampling frame is the entire company’s Human Resource database name list.
Sample size depends on the variability of the targeted population. Based on what the researcher wants to achieve, the formulas for sample size calculation will defer.
Probability sampling methods
In probability sampling, every individual in the target population will be given the opportunity to participate in the sampling. Quantitative research is mainly used for this sampling method. In order to produce results that represent the entire population, probability sampling would be the best choice. There are four main types of probability samples: simple random sample, systematic sample, stratified sample, and cluster sample.
Non-probability sampling methods
In a non-probability sample, individuals are selected based on non-random criteria, and not every individual has a chance of being included. This kind of sample is simpler and cheaper to access. However, it has a higher risk of bias. That means the conclusions that you make from the target population will be weaker than the probability sample and the conclusion might be more limited. Non-probability sampling methods are often used in qualitative or exploratory research. These types of research are not to aim for a broad population but to develop a preliminary understanding of a small-scale or under-researched population. There are four main types of non-probability samples: Convenience sample, purposive sample, snowball sample, and quota sample.