Why are curvilinear relationships hard to detect with correlation coefficients (r)?
A) Because curvilinear relationships require a large amount of scores
B) Because curvilinear relationships have small effect sizes
C) Because r looks for the best straight line to fit the data
D) Because r assumes a zero association
E) Because r assumes a negative relationship

Question

Quizplus · Accepted Answer

Correlation coefficients only measure linear relationships, meaning that they only look for a straight line that best fits the data. Curvilinear relationships, on the other hand, require a U-shaped or inverted U-shaped curve to best represent the data. Therefore, a correlation coefficient may not accurately detect or represent a curvilinear relationship.

Why Are Curvilinear Relationships Hard to Detect with Correlation Coefficients