Negotiation processes evolve simultaneously along several dimensions. We distinguish between a substantive dimension, which deals with the issues to be resolved in the negotiation, a communication dimension reflecting the different tactics negotiators use to provide information, build a relationship, and influence each other, and an emotional dimension, in which negotiators can influence each other even without explicitly communicating their emotions. We present different methods that negotiation researchers have developed in the last decades to study these different process dimensions individually, as well as the steps that have been taken so far towards an integrated perspective of all three dimensions. We then provide an outlook on how recent advances in information technology, data