positive correlation vs negative correlation

In addition, the correlation could be strong, with a value close to 1, which indicates that the data points cluster linearly, with very few exceptions across individuals. That is, people who consumed very few veggies slept less, whereas others who ate more, slept more. Here, the correlation could be positive, which means that the two variables move in the same direction. Statistically, correlations are determined by calculating the correlation coefficient, commonly denoted as r-a number between -1 and 1 that indicates the direction, the sign, of the association and its overall strength, how tight the points align. This design is known as correlational research-examining whether relationships exist between two variables.Īfter collecting both series of measurements, the researcher can visualize the data for each unit, in this case each person, on a graph-a scatterplot-with the variables-daily vegetable consumption and amount of sleep-placed on either axis. In this case, she quantitatively measures two variables by asking participants to report how many vegetables they consumed that day, and later, how many hours they slept. Sometimes, researchers may choose to more passively interact with a phenomenon, rather than to intervene and manipulate the behaviors of interest.įor instance, perhaps a scientist wants to know if there’s an association between eating a plant-based diet and sleep.

Positive correlation vs negative correlation