What Is a Representative Sample?

This Is a Key Factor in Scientific Research

Representative sample checklist
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A representative sample is a group that closely matches the characteristics of its population as a whole. In other words, the sample is a fairly accurate reflection of the population from which the sample is drawn.

Why does this matter? What impact does a representative sample have on research? Let's take a closer look at some of the key reasons why scientists use this important technique in their research.

Why Use a Representative Sample?

When collecting data for psychological studies, researchers rarely gather information from every single member of a particular population. There are some instances where it is important to collect data from every member of a population (the U.S. Census is one example). 

While it may sound fairly straightforward, obtaining a truly representative sample can be quite challenging and requires a great deal of time and effort. One of the first issues that researchers face is trying to get a smaller sample of participants that truly reflects what is going on in the larger population. 

The larger the sample is, the more likely it will accurately reflect what exists in the population. Imagine, for example, that you were trying to create a sample that accurately represented the entire population of the United States. If your sample is too small, you won't be able to represent the variety of people present.

In order to obtain a truly representative sample, you might need to gather information from a fairly large pool of individuals. 

How Are Representative Samples Obtained?

In psychology, a representative sample is a selected segment of a group that closely parallels the population as a whole in terms of the key variables under examination.

 So your sample would vary depending on what your topic of research or population of interest is.

For example, if roughly half of the total population of interest is female, a sample should be made up of approximately 50 percent women in order to be representative.

Random sampling is often used to obtain a representative sample from a larger group. This involves randomly selecting who will be in the sample. Every member of the population stands and equal chance of being selected. 

Examples of Representative Samples

Imagine that researchers want to look at differences in eye color in the United States. In order to obtain a representative sample, they need to look at what percentage of U.S. citizens share certain qualities such as ethnic background and gender and ensure that their sample accurately reflects those numbers.

Why Are Representative Samples So Important in Health Research?

Imagine if scientists wanted to study the prevalence of a particular disease in the population at large. If they were to rely on a non-representative sample, they might reach conclusions that do not accurately reflect what is really going on in the world. This might ultimately end up affecting how much further research is devoted to the study of that illness as well as how much funding might be available for additional research into prevention and treatment.

Sources:

Coon, D. & Mitterer, J. O. (2010). Introduction to psychology: Gateways to mind and behavior with concept maps. Belmont, CA: Wadsworth; 2010.

U.S. Census Bureau. Quick Facts: United States; 2015.

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