IV. Describing Bivariate Data

Prerequisites
none

  1. Introduction to Bivariate Data
  2. Values of the Pearson Correlation
  3. Guessing Correlations Simulation
  4. Properties of Pearson's r
  5. Computing Pearson's r
  6. Restriction of Range Demo
  7. Variance Sum Law II
  8. Exercises
  9. PDF Files (in .zip archive)

A dataset with two variables contains what is called bivariate data. This chapter discusses ways to describe the relationship between two variables. For example, you may wish to describe the relationship between the heights and weights of people to determine the extent to which taller people weigh more.

The introductory section gives more examples of bivariate relationships and presents the most common way of portraying these relationships graphically. The next five sections discuss Pearson's correlation, the most common index of the relationship between two variables. The final section, "Variance Sum Law II" makes use of Pearson's correlation to generalize this law to bivariate data.