In this Special Issue we have included a series of papers that move forward our efforts to conceptually and methodologically capture various forms of peer relationships and contexts.We hoped this would profit theory and research by allowing different streams, such as those focused on peer groups, friendships and romantic relationships, to benefit synergistically from one another. In this commentary we emphasize the similarities and differences between our research areas, as represented by the papers in this Special Issue, by addressing four major questions: "What is 'the peer context' to be captured?", "How can peer processes be captured?", "Doweneed to reconsider the meanings of similarityand social influence?" and "Willweneed to think more about natural windows of time?" Following this commentary, Brett Laursen (2010) provides a general discussion of the papers in this Special Issue and gives an overview of some of the most challenging issues we continue to face.