A toothache is a pain in or around a tooth that may be caused by: 1  Tooth decay. 2  Abscessed tooth. 3  Tooth fracture. 4  A damaged filling. 5  Repetitive motions, such as chewing gum or grinding teeth.
A correlational study determines whether or not two variables are correlated. This means to study whether an increase or decrease in one variable corresponds to an increase or decrease in the other variable.
With correlational research, we usually refer to predictor and criterion variables rather than independent and dependent variables. The measure (or behavior) being predicted is the criterion variable, and the measure (or behavior) from which the prediction is made is the predictor variable.