we are an AI research group who is working on studying the relation between players and the achievements they complete in WoW.

Since that is one of our main hypothesis, we thought it would be nice to ask it in this part of the forum, where the achieve-geeks meet.
We'd like to know if you people seek achievements generally (to get as many as possible), if you try to accomplish them by type (for example guild achievements, player achievements), if you try to get those extremely rare, regardless of the topic they are based on, or if you just play and the achievements come by themselves.

Getting some feedback from you regarding how you deal with achievements would help us a lot, to know if we are going in the right direction.

Thank you all.

BTW, we've got a survey going on which is posted in the General Discussion forum. It gives you a personal profile of you as a gamer based on some questions and your achievements: