Question

In research, to generalize one's findings to a total population, what is the most important quality that the sample must possess?
a. it must consist of people who are selected and people who volunteer.
b. it must be quantitative in order to make comparisons.
c. it must include at least 25 percent of the total population.
d. it must be representative of the total population.

Answer 1

When it comes to generalizing a research, the most important quality that the sample should have is answer D: it must be representative of the total population.

This means that the results obtained using a sample that consists of a small amount of individuals (compared to the total of the population) should be able to be transferred to the total of the population that that sample represents.

For example, imagine we do a research on "water contamination" in New York and our sample consists of 100 houses that are going to be tested. The results show that 10 of those houses' water supply is contaminated. A well selected sample should allow us to transfer that result into the general population of the city, throwing the following result: "10% of houses' water supply in New York is contaminated".

In order to be able to transfer, generalize the results, and have the sample accurately reflect the total population, the sample chosen should  have similar qualities to the general population.