Saylor URL: http://www.saylor.org/books Saylor.org
there is an association, the points are not well described by a single straight line. For instance,
part (d) shows the type of relationship that frequently occurs between anxiety and performance.
Increases in anxiety from low to moderate levels are associated with performance increases,
whereas increases in anxiety from moderate to high levels are associated with decreases in
performance. Relationships that change in direction and thus are not described by a single
straight line are called curvilinear relationships.
Figure 2.10 Examples of Scatter Plots
Some examples of relationships between two variables as shown in scatter plots. Note that the Pearson correlation
coefficient (r) between variables that have curvilinear relationships will likely be close to zero.
Source: Adapted from Stangor, C. (2011). Research methods for the behavioral sciences (4th ed.). Mountain View,
CA: Cengage.