Depending on personal experience, personality type and emotional concern, we find that some people hold the idea of studying with a group, meanwhile others prefer to study alone, from my point of vew, it depends of subject.
The main reason for my propensity of studying with a group is that, sometimes, I have many difficults about subject, and I need others people help me with it.
The second reason can be seen by every person that when we study with a group we have opportunity to discuss about the subject, one adds information to others, and together, everything learns more.
In other hand, there are moments that is better study alone. Some subjects require much attention, concentration and silence, when we must read a lot, for example.
In addition, these reason are also usable when we consider that people are differents and their necessity are also differents, and the important is that, on their way, every person learn.