Population and Sample

Population

A population refers to the entire group that you want to draw conclusions about.

• It includes all members or observations of a defined group.

• It can be both discrete or continuous numerical data

Examples

• All voters in Canada

• Every product coming off a factory line

• All high school students in Ontario

Studying and analyzing the data from the entire population would provide the best representation; however, it is often too large to measure and study as a whole.

Sample

A sample is a subset (a smaller portion) of the population that is selected for analysis.

Samples are used when it is impractical or impossible to study the entire population.

A good sample can help describe the entire population; however, a bad sample can create incorrect conclusion, stereotypes, and bias. Therefore, proper sampling methods must be used.

Examples

• 1,000 Canadian voters surveyed before an election

• 50 students randomly selected from a school

• 20 products checked for quality control