Quota sampling is a type of non-probability sampling in which the researcher selects a sample based on predetermined quotas for specific characteristics. This is done in order to ensure that the resulting sample is representative of the population as a whole. It involves the selection of units (e.g. people, organizations) in a study based on predetermined criteria such as sex, age, race/ethnicity, etc.
Example of Quota Sampling
An example of Quota Sampling would be if researchers wanted to study the opinions of high school students on a particular issue. In this case, the researcher may select a quota of 100 students from each high school in the area. This would ensure that the sample is representative of the population of interest.
Quota Sampling Selection Methods
There are two Methods of quota sampling Selection:
In self-selected quota sampling, the respondent chooses to participate in the study based on their own criteria (e.g., age, gender, race). This type of quota sampling can be used when it is difficult to reach potential respondents (e.g., via telephone or door-to-door surveys).
In interviewer-selected quota sampling, the researcher selects respondents based on predetermined quotas for specific characteristics. This type of quota sampling is often used in face-to-face surveys, as it allows the researcher to control who is interviewed.
Types of quota sampling
There are two types of quota sampling:
- Controlled quota sampling
- Uncontrolled quota sampling
Controlled quota sampling
Controlled quota sampling is a probability sampling method used to select a target population that is representative of the larger population. The researcher defines the characteristics of the target population, such as age, gender, race, and income level. Then, a random sample of individuals is selected from the population that meets the criteria.
Uncontrolled quota sampling
Uncontrolled quota sampling is a method of selecting a sample from a population in which the researcher does not have complete control over the selection process. This type of sampling is often used in market research and opinion polls.
With uncontrolled quota sampling, the researcher typically outlines the parameters for the study and then relies on an outside agency, such as a polling company, to select the actual participants. The advantage of this method is that it is less expensive and time-consuming than other methods of selection, such as random sampling.
How to use Quota Sampling
In order to use quota sampling, the researcher must first decide on the quotas for each subgroup within the population. For example, if researching attitudes towards a new product, the quotas may be set for age, gender, and location. Once these quotas are set, the researcher can begin approaching people that fit into those categories until the desired number of responses is met.
Quota sampling can be an effective way to obtain data when it is not possible or practical to do a random selection of participants.
When to use Quota Sampling
There are several factors to consider when deciding whether or not to use quota sampling for your research project.
- You must have a clear understanding of the population you are studying.
- You must be able to identify different subgroups within that population.
- You must be sure that the quota sampling method will allow you to obtain the data you need to answer your research question(s).
Purpose of Quota Sampling
The purpose of quota sampling is to ensure that the sample represents the diversity of the population.
For example, if a researcher wants to study the attitudes of college students towards smoking, they might use quota sampling to select a certain number of students from each grade level and from each gender. This ensures that the sample is representative of the population as a whole.
Quota sampling is often used in market research, as it allows researchers to target specific groups that they are interested in studying. For example, a researcher may want to study women aged 18-34 who live in urban areas and work full-time. By using quota sampling, the researcher can ensure that their sample meets these criteria.
Advantages of Quota Sampling
Some Advantages of Quota Sampling are:
- Quota sampling allows the researcher to select a specific number of subjects from different subgroups within the population.
- This can be helpful when studying rare phenomena or groups that are hard to access.
- Quota samples are usually easier than other types of non-probability samples.
- It can provide information about a population that would be difficult to obtain through other methods.
Disadvantages of Quota Sampling
Some Disadvantages of Quota Sampling are:
- Quota sampling can be time-consuming and expensive. The researcher must identify the groups from which he or she will select subjects, determine the desired number of subjects from each group, and then locate and interview those individuals.
- It may produce a biased sample if the groups are not properly defined or if the selection process is not random.
- Because quota samples are often small in size, they may not be representative of the population as a whole and may produce unreliable results.