If I've learned anything from prison dramas, it's that sometimes a stern talking to just doesn't do the trick. You also need plenty of hard-work, a commitment to understand your prisoners, and a rousing and inspirational third-act speech, in which you learn that, actually, it was them teaching you all along. Alternatively, you need guns. For Prison Architect's seventeenth alpha update, Introversion have gone for the second option.
Armed guards will intimidate prisoners by increasing their "Supression" rating, and making them more compliant. The downside is that, to hire them, you'll need to build an Armoury, which will be an instant target for violent prisoners should a riot break out. In future, when reform systems are in place, suppressed prisoners will be less susceptible to education programs and rehabilitation, but for now, you're free to fill your jail with more guns than a Battlefield weapons crate.
Also in the update: trees! A new Forestry tile will automate the woodcutting industry introduced in the last update. You can read about all of the alpha 17 changes over at the Introversion forum .