... That is an interesting negative finding as well. Just so this thread doesn't go without some positive results, here is a table from one of my technical reports on some features that do correlate with quality. If the number is greater than zero it correlates with quality, if it is 0 it does not correlate, and if it is less than 0 it is negatively correlated with quality. The scale of the numbers is meaningless and not interpretable, although the relative magnitude is important. These are just the relative performance of each feature for each class, as extracted from the weights of a random forests classifier. http://grey.colorado.edu/mediawiki/sites/mingus/images/1/1e/DeHoustMangalat…