To Befriend Or Not? A Model of Friend Request Acceptance on Facebook.

Accepting friend requests from strangers in Facebook-like online social networks is known to be a risky behavior. Still, empirical evidence suggests that Facebook users often accept such requests with high rate. As a first step towards technology support of users in their decisions about friend requests, we investigate why users accept such requests. We conducted two studies of users' befriending behavior on Facebook. Based on 20 interviews with active Facebook users, we developed a friend request acceptance model that explains how various factors influence user acceptance behavior. To test and refine our model, we also conducted a confirmatory study with 397 participants using Amazon Mechanical Turk. We found that four factors significantly impact the receiver's decision, namely, knowing the requester's in real world, having common hobbies or interests, having mutual friends, and the closeness of mutual friends. Based on our findings, we offer design guidelines for improving the usability of the corresponding user interfaces.