Study Population vs. Target Population

Attribute	Study Population	Target Population
Definition	The group of individuals who are the focus of a particular study or research project.	The group of individuals to whom the results of a study are intended to be applied or generalized.
Selection	Participants are typically selected based on specific criteria set by the researcher.	Individuals in the target population may not be specifically selected, but rather represent a broader group.
Size	Study population is usually smaller in size compared to the target population.	Target population is typically larger and more diverse.
Characteristics	Study population may have specific characteristics or traits that make them suitable for the study.	Target population may include individuals with a wide range of characteristics and backgrounds.

Definition

Study population and target population are two important concepts in research methodology. The study population refers to the group of individuals who are actually studied or observed in a research study. This group is often a subset of the larger target population, which is the entire group of individuals that the researcher is interested in studying. The target population represents the broader group to which the findings of the study are intended to be applied.

Characteristics

The study population is typically a smaller and more manageable group than the target population. Researchers often select a sample from the target population to study, as it may be impractical or impossible to study every individual in the target population. The study population is chosen based on specific criteria that are relevant to the research question, such as age, gender, or location. In contrast, the target population includes all individuals who meet the criteria for inclusion in the study, regardless of whether they are actually included in the study sample.

Representativeness

One of the key differences between the study population and the target population is representativeness. The study population may or may not be representative of the target population as a whole. If the study population is not representative, the findings of the study may not be generalizable to the target population. Researchers must carefully consider how they select the study population to ensure that it accurately reflects the characteristics of the target population. This may involve using random sampling techniques to minimize bias and increase the likelihood of obtaining a representative sample.

Sampling Methods

Sampling methods play a crucial role in determining the relationship between the study population and the target population. Researchers use various sampling techniques, such as random sampling, stratified sampling, or convenience sampling, to select individuals for inclusion in the study population. The choice of sampling method can impact the generalizability of the study findings to the target population. For example, random sampling is often considered the gold standard for ensuring representativeness, as it gives every individual in the target population an equal chance of being selected for the study.

Application

Understanding the differences between the study population and the target population is essential for interpreting the results of a research study. Researchers must clearly define both populations at the outset of the study to ensure that the findings are valid and reliable. By carefully selecting the study population and using appropriate sampling methods, researchers can increase the likelihood that their findings will be applicable to the broader target population. This can help to inform decision-making and policy development based on the results of the study.