The sorting of the various tactics into categories for selective training is currently being worked on, I believe.
Could we get more tactics sorting options?
Sort:
The downside of that would be that you'd have a good clue what to look for in the given problems. The tactics trainer trains instant patterns recognition.
I personally have also gotten better by learning what not to do... e.g. taking a hanging rook when there is a mate in two lurking about or trying the Destined-To-Be-Doomed mating attack instead of capturing a hanging peice. If I was studying the "Mate in two" or "Hanging peices" categories that judgement wouldn't be needed and I might get rewarded for handling situations that I might fail in a game.
The biggest problem with the tactics trianer on this site is that there is no way to choose which category of tactic to study. I tend to get way more checkmates than pins, skewers, or removing the guard problems. If the tactics could be grouped according to style (as in the famous Fred Reinfeld book), difficulty, number of moves, opening they arose from, endgame, it would be a lot more valuable. Also, the individual tactic problems should be exportable as PGNs.