Thottbot have made some changes to how they score items in World of Warcraft:
All items now have a score value. Score is essentially the sum of all stats on an item. If an item has 20 strength and 20 intellect, by default it has a score of 40. Some stats of course are more valuable than others, for example Blizzard considers 2 attack power to be equivalent to 1 strength for item value, so Thottbot does too.
Odds are, whatever class you're playing doesn't like every stat in the game equally, so you can freely customize your score values. There's even a forum, for finding and discussing the perfect formula for your specific spec, role and playstyle (PvE, PvP, etc.).
Once your formula is set, finding items you want in a zone gets a whole lot easier.