I really, really wanted to like this book more than I did. After all, it was about a topic that I have great interest in, and describes a workbench application (Weka) that I can command-line access from my favorite programming environment (R, via RWeka).
The problem I was having with it is that its presentation, across the board, was incredibly wordy. They managed to make the interesting sound boring, and presented technical material with no grace whatsoever. The chapter on the Weka Explorer was a case in point: page after page where they would throw out names of an algorithm or a filter or whatever, and a sentence or a paragraph on what it did, then on to the next one. Now, come on guys: what do you expect a reader to get out of section after section of this sort of thing? If it's meant as a reference, write it as a reference. Break it into multi-column lists. Heck, just include the Javadoc page, I don't care. But as textual paragraphs? It was as interesting as reading a set of dictionary entries (Pi-Po, for example), all squashed into a paragraph, words mixed with etymology, mixed with definitions. It's not terrible useful as a reference, and as it a reading experience, it--frankly--sucks.
So, I ask again of the authors: what do you want the reader to take away (remember) from the section? Write that. As clearly as possible. With all the examples and illustrations that are necessary to make it clear. Are you writing a reference section? That's fine, but make it clear that's what you're doing, move it in an appendix, whatever.
As a third edition, I expected better from this, but it showed little refinement over the previous edition. It was just...bigger. I confess that I skimmed in places. It was just too damn tedious.
William's book--Data Mining with Rattle and R--set itself much the same task of introducing data mining and showing off a workbench, but did a much better job in a third as many pages.