If researchers can collect data from everyone in the population, this is called a census.
Sample
Is selected to represent a part of the entire population. (When you join a company and want to know what customers think, it’s impossible for everyone to investigate, just choose one at random)
Sample Plan
To select a sample, the researcher needs a plan to decide who will be selected, how many people will be selected and how they will be selected.
Steps of the sampling process
Identify the population
Researchers must decide what information is needed and who is most likely to receive it.
Identify the sampling frame
List of all people in the population. It is not always possible to obtain a list of all people in an interest group.
Select the sampling method
Researchers can choose between probability sampling and non-probability sampling. In this sampling, each persona has an equal opportunity to be selected and participate in the research.
Determine the sampling size
The researcher must decide how many respondents should be included in the study. Used to calculate percentages and determine the average person's thoughts in the population.
Select the sample elements
The sampling method is implemented. In this step and the individual respondents are selected.
Gather the designated data
The researcher is now ready to do the fieldwork and collect the data.
Sampling Methods
Probability Sampling Methods
Simple random sampling
When using this method, each name on the list will get a number written on the card. Then, the researcher selects the required sample size from all the cards. The persons whose names are drawn are selected as samples.
Stratified sampling
When researchers use this method, it is possible to divide the population into different groups, such as men or women. This ensures that each group is clearly represented in the study.
Cluster sampling
People living in different provinces or towns. Instead of selecting sample units in all different provinces or towns, the researcher randomly selects two or three provinces and then selects samples in the cluster.
Systematic sampling
When researchers use systematic sampling methods, they randomly select the first person, and then select the sample unit according to a set interval or system. Interval or system is a skip mode.
Non-Probability Sampling Methods
Convenience sampling
In a convenient sample, the researcher uses anyone who is easy to find. This sample does not represent the majority of people.
Judgement sampling
Researchers select people with specific characteristics based on their own judgment.
Snowball sampling
It is often difficult to find people with specific characteristics, such as finding a person. Then ask her to provide the names of other people. In this way, the research sample starts with one interviewee and then snowballs to many interviewees.
Quota Sampling
When researchers need to obtain information from a certain number of people with certain characteristics, they will use this sampling method.
