CO-4: Distinguish among different measurement scales, choose the appropriate descriptive and inferential statistical methods based on these distinctions, and interpret the results.
LO 4.20: Classify a data analysis situation involving two variables according to the “role-type classification.”
LO 4.21: For a data analysis situation involving two variables, determine the appropriate graphical display(s) and/or numerical measures(s) that should be used to summarize the data.
Related SAS Tutorials
Related SPSS Tutorials
Introduction – Two Quantitative Variables
Here again is the role-type classification table for framing our discussion about the relationship between two variables:
Before reading further, try this interactive online data analysis applet.
We are done with cases C→Q and C→C, and now we will move on to case Q→Q, where we examine the relationship between two quantitative variables.
In this section we will discuss scatterplots, which are the appropriate visual display in this case along with numerical methods for linear relationships including correlation and linear regression.