Quota sampling can be defined as a sampling method where a sample of respondents, with specific characteristics and traits, for research is selected from the population of interest.
What is quota sampling?
Quota sampling is also known as the non-probability sampling method. The quota sampling method is used in the initial stage of a research study. The population for sampling is selected based on specific characteristics and traits of the members of the population.
The population is then divided into subsets based on different aspects. The selection of participants for research using the quota sampling method increases the effectiveness of the research and can be generalized for the entire population.
For example, two different groups of respondents from a population can be formed based on the gender of the respondents, and further participants can be selected based on their age or income factor. Other factors can also be added to the subset as per the requirement of the research study.
The quota sampling method is quite similar to stratified sampling. The difference between these two methods is that in quota sampling, participants are not selected randomly from the population, whereas in stratified sampling, participants are chosen randomly from the population. Because of this reason, stratified sampling is also known as the probability sampling method.
There are more chances of biased outcomes in quota sampling. For example, a researcher can interview people who coordinate with the interviewer as it is easy for him to obtain answers or researcher might include the people that are known to him to complete the number of participants of the research.
The quota sampling method is more suitable for research types where the accuracy of the research outcome is not essential. The effectiveness of quota sampling can be ensured if the researcher has a clear understanding of the objective of research and in-depth knowledge about the population.
How to create a quota sample?
The followings are the main three steps in creating a quota sample.
Step 1. Create an exclusive group
The first step in quota sampling is the creation of groups of individuals with similar characteristics or traits relevant to the research. Make sure that participants in the study belong to only one group. For example, a researcher can create two groups of women based on two characteristics. The first characteristics are to select women who belong to the age group of 35-50, and the second characteristic can be working or non-working women.
In this way, two research groups can be formed. The first group of women will consist of working women within the age group of 35-50. The second group of women will include non-working women within the age group of 35-50.
Step 2. Determine the proportion of subgroups
The next step in quota sampling is to establish the proportion of subgroups in quota sampling. For example, working women could be one in four in the particular city where research is being conducted.
Step 3. Deciding the size of the sample
The next step is to select the size of the sample. For example, if you are conducting a quota sampling on the 10,000 women, then you should at least choose 100-200 women in one sampling group.
Step 4. Select participants
In the next step, the researcher would select the participants of the research group. The accuracy of research depends on the participants of the research group. Select participants randomly who fulfill the criteria of research.
Advantages of Quota Sampling
- Quota sampling is quite easy to conduct and administer as compare to the other similar research sampling methods.
- The quota sampling method is suitable for research where the researcher has the time limit to conduct the study. Quota sampling can be performed quickly as compared to other research sampling methods. Therefore, it saves a lot of time for the researcher.
- The quota sampling method is cost-effective. It can be used for researches with a limited budget.
- In quota sampling, over-representation of the population is avoided as in quota sampling, participants of the research group are selected based on specific characteristics and traits and not randomly.
- Quota sampling makes the interpretation of information convenient for the researcher.
- Quota sampling method can be used in researches where probability sampling techniques are challenging to implement.
- Quota sampling can be used as a primary research method of researches of different types.
- Quota sampling helps in an easy comparison of two groups of research.
Disadvantages of Quota Sampling
- Quota sampling does not allow random selection of participants of the research.
- Quota sampling increases the risk of researcher bias as a researcher might include people in research who he finds to easy to approach or have co-operative nature.
- The outcome of quota sampling is not accurate as it lacks randomness of the selection of participants.
- The result of quota sampling research is not reliable as it is affected by many factors.
- The accuracy of quota sampling largely depends on the judgment of the study. The biased approach of the researcher influences the accuracy of the result of the quota sampling research method.
When to use quota sampling?
Quota sampling method can be used to research the following two scenarios.
- Quota sampling is easy to use when comparative analysis of two subgroups is required to make. Quota sampling helps in determining the distinguishing features among the interconnected traits of two subgroups.
- Quota sampling is beneficial in scenarios where researchers have specific criteria to conduct research. Quota sampling is quite convenient to use in such a situation because of the filtering characteristics of the method.