Ok, so, hopefully your guild is using World of Logs to record your raids. I get requests from old friends via facebook occasionally to review raid performance, help out with boss strats, figure out what's going wrong, etc.
You'd be amazed how much you can learn from a WoL parse; I highly suggest you spend a little time reviewing each raid. You cannot improve if you don't know what you're doing wrong, and sometimes you can find really strikingly obvious mistakes in WoL that should be fixed immediately.
Now, let me make one point; Premonition is really cool about mistakes. I think one of the first things Xav said to me was that it's a terrible idea to dwell on mistakes, because then we'd never get any real raiding done. Following this philosophy, Premo gives a *ton* of leeway; If you're doing something wrong, you're far more likely to be told, "Hey, this is what you're doing wrong, you'll do way better if you correct it" than, "Hey, you did something wrong, get out of my guild." Point being, don't look at your raiders, determine someone was attacking the wrong target, and gkick them. Once people know you have access to all this information, people will do the right thing more often.
First off, it's pretty easy to find someone in World of Logs. Lets say I want to look up how Kailee did on a specific fight
That lets us go to any realm, which lets us select any guild on that realm. Pretty easy to find Kailee's guild from there: http://worldoflogs.com/guilds/2335/
Now you can go to a specific fight and compare damage numbers; Maybe looking at DPS, then damage per hit to see if any discrepancy is based on gear, look at number of each attack used based on time and figure out if discrepancies are based on rotation differences, anything you want!
But there's even more information than meets the eye. Using the Query Browser (Work out the stuff on your own, I'm lazy) you can get:
[20:49:32.562] Eydis Darkbane begins to cast Twin's Pact
[20:49:42.437] Parn's Shield Bash interrupts Eydis Darkbane's Twin's Pact
[20:50:17.125] Fjola Lightbane begins to cast Twin's Pact
[20:50:30.734] Parn's Shield Bash interrupts Fjola Lightbane's Twin's Pact
[20:51:02.093] Fjola Lightbane begins to cast Twin's Pact
[20:51:16.140] Nahid's Wind Shear interrupts Fjola Lightbane's Twin's Pact
Awesome, now we have time sets. During the first one, people attacking Lightbane are doing it wrong, during the second two, people attacking Darkbane are doing it wrong. each tick is one second, the fight starts at 20:47:15 (4830). So our first cut is 20:49:32, which is 2:17 later or 137 ticks, and lasts 10 seconds, so 4967 to 4977. Cutting to this point, we can go to Lightbane's Damage Taken by Actor
Doing that for the rest:
And thus you can see who did damage to the wrong target; You can see that a rogue on the second one either didn't swap or swapped late. Of course, this hardly scratches the surface of what you can do with world of logs; It's really awesome for all sorts of raid-browsing information.
Use it, learn from it, improve yourself and your raid.