The Essentials of Biostatistics for Physicians, Nurses, and Clinicians

126 CHAPTER 7 Correlation, Regression, and Logistic Regression

Table 7.8

Predicting Student's Olympiad 3 Exam

Score Based on Olympiad 2 Exam Score

Exam 2 score Predicted exam 3 score

0 1 2 3 4 5

higher or lower than the exam 2 score? What changes when we move

from below the average to above the average? The result is a mathematical

property called regression toward the mean. This occurs in any regression

problem. Some people thought it was a tendency to move toward medi-

ocrity. But that is a fallacy called the regression fallacy.