What does a scatterplot measure?

A scatterplot visually represents the relationship between two variables, and it primarily measures the strength of that relationship. When examining a scatterplot, you can observe how closely the data points cluster around a line or curve, which indicates the strength. A strong relationship will show points closely aligned, whereas a weak relationship will display more scattered points.

In addition to the strength of the relationship, a scatterplot can also suggest the direction of the relationship (positive, negative, or none). This visual insight is critical for understanding correlations between the variables studied. Therefore, selecting the measure of strength highlights a key aspect of what a scatterplot conveys.