Purposeful sampling is a technique widely used in qualitative research for the identification and selection of information-rich cases for the most effective use of limited resources (Patton, 2002)
- It has also known as judgmental, selective, or subjective sampling
- It is a form of non-probability sampling in which researchers rely on their own judgment.
- Here, the entire sampling process depends on the researcher’s judgment and knowledge of the context.
In Purposeful Sampling…
- The sample is selected based on knowledge about the study and the population
- Participants are selected based on the purpose of the sample
- Applicants who do not meet the profile are rejected
Advantages of Purposive Sampling
- It is a cost-effective sample selection method. Here, the researcher depends on their knowledge to choose the best-fit participants for the systematic investigation.
- It also helps to save time.
- It helps to get valuable research outcomes.
- Lowers the margin of error in your data because the data sources are a close fit with the research context.
Disadvantages of Purposive Sampling
- It may lead to several invalid or inferential statistical procedures.
- The participants in purposive sampling can manipulate the data, causing invalid research outcomes.
- It is not an effective method of collecting data from a large population.
When Should Purposive Sampling Be Used?
This type of sampling is used when only there is a specific objective
When the researcher needs to find a sample that has:
- Specific experiences
- Specialized knowledge
Examples of Purposive Sampling
Here’s a simple example of how purposive sampling works in market research:
- Before launching a new wine product, an organization conducts pilot testing to gather feedback from the market. For the sample population, the researcher chooses expert wine tasters to provide valuable feedback for product improvement.
Purposive sampling can also be used in educational research.
- Suppose you want to collect feedback from students on the pedagogical methods in their school. You go ahead to handpick the brightest students who can provide relevant information for your systematic investigation.
Purposive sampling can also be used in research on the construction industry,
- suppose the researcher wants to collect data for solving problems that could happen on construction projects, then he chooses stakeholders in the construction industry who can give relevant information about his specific objectives.