**Scatter Diagram** (scatter plot) - display of data which shows visual correlation (or lack thereof) of two variables. Since people can much more quickly see patterns visually, as apposed to in a series of numbers, the diagram is a good tool to illustrate the effect to others in a briefing or report.

Statistically a regression line is the line through the data where the square of the difference between the line and each data point it least.

- Scatter Plot overview from Skymark
- Scatter Diagram overview from the Quality Assurance Project
- Scatter Diagrams a tutorial from Clemson
- Scatter Plot overview from the NIST Engineering and Statistics Handbook