The Analysis Process
Read the section titled "Analyzing Basic Scatter Charts" in Scott Barber’s article. Scott lays the foundation for scatter chart analysis by introducing seven basic patterns (with illustrations) found with some regularity when looking at scatter charts:
- "Good" pattern
- "Banding" pattern
- "Outlier" pattern
- "Caching" pattern
- "Classic Slowdown" pattern
- "Stacking" pattern
- "Compound" pattern
I don’t want to repeat Scott’s work here, so if you haven’t read the article yet, please do so now. He does an excellent job of breaking down the different aspects of the test that you’ll need to understand, as well as the basics of pattern-based analysis. Scatter charts are powerful because they’re visual and allow us to apply heuristic pattern-matching. Instead of looking at a data table with thousands of rows and applying statistical methods to simplify the problem, we can use the power of visual patterns to analyze those thousands of points of data at the same time.
Scott’s article focuses on recognizing the patterns when you see them. I want to help you figure out how to get the patterns to jump out at you. This is the area of scatter chart analysis that I struggled with for the longest time. I now have some tricks that I use to help the patterns bubble up to the top (so to speak).