Add description of what graph means

README.md

@@ -3,6 +3,25 @@ Hopefully-meaningful Metrics
 
 Based on Michael Feathers' [recent work](http://www.stickyminds.com/sitewide.asp?Function=edetail&ObjectType=COL&ObjectId=16679&tth=DYN&tt=siteemail&iDyn=2) in project churn and complexity.
 
+Here is how to read the graph (extracted from the above article):
+
+* The upper right quadrant is particularly important.
+These files have a high degree of complexity, and they change quite frequently.
+There are a number of reasons why this can happen.
+The one to look out for, though, is something I call runaway conditionals.
+Sometimes a class becomes so complex that refactoring seems too difficult.
+Developers hack if-then-elses into if-then-elses, and the rat’s nest grows. These classes are particularly ripe for a refactoring investment.
+
+* The lower left quadrant. is the healthy closure region.
+Abstractions here have low complexity and don't change much.
+
+* The upper left is what I call the cowboy region. This is complex code that sprang from someone's head and didn't seem to grow incrementally.
+
+* The bottom right is very interesting. I call it the fertile ground.
+It can consist of files that are somewhat configurational, but often there are also files that act as incubators for new abstractions.
+People add code, it grows, and then they factor outward, extracting new classes. The files churn frequently, but their complexity remains low.
+
+
 Installation
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