From FFLogs itself:
rDPS is great for showing how much damage you really contributed to the raid, For utility jobs like Dancer and Ninja, the metric depends on people making good use of your buffs, so some damage you contribute to the raid is out of your control.
nDPS is great for showing how well you executed your rotation. This allows, for example, Dancers and Ninjas, to see how well they did even if placed with underperforming partners or groups.
aDPS removes single target padding, but still rewards you for playing to AOE buffs. It also doesn't include your buff contributions, so this metric allows you to evaluate how well players are aligning their damage bursts with external AOE buffs.
You can check for yourself.