This question already has an answer here:
How many publications as an undergraduate are enough if one's goal is to do a PhD at a top US school?
Of course quality is important, but assuming all are "high enough" quality (e.g. in a reputable well known conference but not world class) should a student try to publish more given that he can?
Maybe publishing in different sub-fields shows one has a broad understanding of the field?
For example one can publish a paper with a professor as his Thesis, and 1-2 extra papers with other professors working with them as research assistant.
Is there a point where one has "proved" he can do research and there is no need to publish more? Will graduate admissions view 2 vs 4 publications much more positively?
Edit: I am talking about Computer Science