At the SCAA show in Anaheim (April 2010) I was able to take the Roasters' Guild's "Green Coffee Grading" course. It helped me learn about the various types of defects. It's almost like a "processes at origin" course on it's flipside - they are primarily talking about and showing you throughout the class what happens when those processes at origin are not done well.
As we witnessed the kind of stones, little sticks, "blacks", "withereds", "pre-matures" and other defective beans, my thoughts turned to what must be going into a lot of decaf coffee in North America. Each defect found in a 300g sample downgrades the quality of the coffee, and therefore the price. That's why more often than not, it's the cheap, low quality coffee (with blacks, whites, sticks, brokens, etc.) that is getting thrown into the brutal decaffeination processing plant, and then the giant roasters at commodity coffee production plants throw it into a wicked 7 minute blast roast. It's no wonder most decaf in the US tastes miserable!