It is important to understand the relationship between two variables. With quantitative data, this primarily consists of using a scatterplot and the correlation coefficient to describe four key characteristics of the relationship. This module describes how to use a scatterplot and correlation coefficient to provide a synthetic description of the relationship between two quantitative variables.
After completing this module, you should be able to ...
- Describe bivariate data.
- Distinguish between response and explanatory variables.
- Construct a scatterplot with R.
- Know when it is appropriate to calculation a correlation coefficient.
- Calculate a correlation coefficient with R.
- Construct a succinct written summary that addresses the four key characteristics (form, direction, outliers, and strength) of the relationship between two quantitative variables.
Preparation for Class
Use the materials below to answer the questions on this preparation guide.
- Construct a Scatterplot [7 mins]
- What is the Correlation? [8 mins; start at 0:32]
- Bivariate EDA (Quantitative) in R [8 mins]
- Interpeting a Bivariate EDA (Quantitative) [10 mins]