Researchers at the University of Montana found so many different definitions among the students they studied that they had to come up with a precise definition to be sure everybody was talking about the same thing. But the lead author of their study, published in the journal Health Communications, said in a telephone interview that ambiguity is not necessarily a bad thing. It's a way for them [students] to communicate about it but without having to reveal details. It adds that most students describe hookups as spontaneous sexual encounters fueled by alcohol that usually unfold without communication about sexual health and consent or protection against sexually transmitted infections. It starts at a party, frequently at a frat or sorority house, where there is plenty of booze. As the evening goes on, couples form and eventually move off to do whatever they have in mind -- no commitments, no expectations for the future, no serious thoughts about health or risk, a seemingly carefree adventure fueled by alcohol.