What is a Representative Sample?

Definition: A representative sample is a small portion of a population that is considered to reflect accurately the entire population’s characteristics. The results obtained from such sample can be confidently generalized as a reflection of the population as a whole.

What Does Representative Sample Mean?

Samples are tiny groups taken from a wider population to study certain elements. These samples are obtained through various statistical methods that allow the researcher to pick this group properly for it to be considered representative. This is a particularly important element since the purpose of sampling is to reduce the research efforts by shrinking the number of subjects being studied but this is only successful if the selected group reflects the whole population’s reality. Achieving this representativeness is not an easy task since the method employed to calculate and approach the sample will affect results considerably.

This is the reason why businesses often hire professionals to perform market research studies where information about customers or workers is required, since the company will rely in this information to make decisions and it is crucial that the information gathered reflects accurately the reality of the whole population being addressed. The degree of representativeness is often calculated by comparing the results obtained from the sample to wide-reach studies made within the target population, to see if results match. Nevertheless, there is no concise technique to determine whether a sample is a representative one or not.


Clean H2O Co. is a company that designs water purification solutions for businesses that sell bottled water. The company’s main business is mid-scale projects implemented in regions where the water supply tends to be contaminated by natural resources such as metals. The company’s biggest market is overseas and they mostly work with European countries. Recently, the company’s Board of Directors decided to expand the business’ reach to the South American market.

In order to do so they hired ConsultCo LLC, a market research firm based in Argentina to study Clean H2O’s potential market within Brazil, Argentina, Chile and Colombia. By using advanced statistical techniques, ConsultCo identified a market of 200 potential projects within the cities they choose as the study sample. This means that there are more than 1,400 potential projects if the sample is extrapolated to the whole population of these countries. The report proved to be very accurate since Clean H2O successfully expanded to South America, developing more than 350 projects within its first three years of operations in the region.