What is a Selective Sample?
A selective sample is a type of sampling method used to obtain information from a larger population. It is used when researchers have an idea of the population they want to study but do not have access to the entire population. Through a selective sample, researchers can obtain a representative sample of the population without having to survey or collect data from the entire population.
Types of Selective Sampling
Selective sampling can be broken down into several types, each of which has its own advantages and disadvantages. These types include:
- Random Sampling: In random sampling, a researcher selects individuals from the population at random. This method gives all individuals in the population an equal chance of being selected.
- Convenience Sampling: In convenience sampling, a researcher selects individuals who are easily accessible. This method is often used when a researcher does not have access to the entire population, but can easily reach a subset of it.
- Purposive Sampling: In purposive sampling, a researcher selects individuals based on predetermined criteria. This method is commonly used when a researcher wants to select individuals based on a specific set of characteristics or qualities.
Examples of Selective Sampling
- A researcher wants to study the effects of stress on college students. To do this, they use purposive sampling to select students from a particular college who have reported feeling a high level of stress.
- A researcher wants to study the eating habits of people living in a particular city. To do this, they use convenience sampling to select people who are easily accessible such as those living in the downtown area.
- A researcher wants to study the opinions of people living in a particular country. To do this, they use random sampling to select individuals from the entire population.
Selective sampling can be an effective method of obtaining information from a larger population. However, it is important to consider the advantages and disadvantages of each type of selective sampling in order to ensure that the sample is representative of the population being studied.
Conclusion
Selective sampling is a valuable tool for researchers who need to obtain information from a larger population but do not have access to the entire population. It can be broken down into several types, each of which has its own advantages and disadvantages. Examples of selective sampling include random, convenience, and purposive sampling.