Correlational Study

A type of research study in which at least two variables are directly measured and compared in a large group of individuals. The goal is to calculate a correlation: the average degree to which the two variables change together in those individuals, either in the same direction (a positive correlation) or in opposite directions (a negative correlation). In addition, the magnitude of the correlation (how large it is) tells researchers whether the association between the two variables is strong (when one variable changes, the other variable often changes along with it) or weak (when one variable changes, the other variable sometimes changes along with it).

If the sample of individuals observed in a correlational study is a representative sample of a population, then the correlation serves as an estimate of the direction and strength of the average association between the two variables in that population.

The most important advantage of correlational studies is that they give researchers information about whether or not a relationship between two variables is a general one (that is, if the relationship is characteristic of a large group of people). Two important disadvantages of correlational studies is that they do not control for the directionality problem or the third-variable problem.