I agree that PCI is a great introduction to the field. If you're not sure which tool to use to solve a problem, it's great for pointing you in the right direct

I agree that PCI is a great introduction to the field. If you're not sure which tool to use to solve a problem, it's great for pointing you in the right direction. Just a word of warning (@toby, correct me if I'm wrong), but most of the examples are just to give you the idea and to get you started, but aren't expected to work at scale. I'd love to see a followup book on "Optimizing Collective Intelligence".