According to Cross and Fletcher (2009), there is currently no one “accepted definition of the adolescent crowd” which is the reason why “the boundaries of the crowd are not sufficiently delineated” (p. 753) in the existing methodological approaches. Hence, they argue, “without a decision about who is to be studied (i.e., how to define the crowd)” the current approaches in studying adolescent crowds are prone to making “both Type I- and Type II-like errors” (p. 753). A Type-I-like error would occur when someone is wrongly classified to a crowd, the “null hypothesis” being that he or she is not a member of that group. A Type-II-like error would occur when someone is not rightly classified as a member of a crowd to which they belong. Thus, higher Type-I- and Type-II-like errors represent concepts similar to specificity and sensitivity in epidemiology. In our view, despite the differences in methodologies used to study adolescent peer crowds, one may infer a consensus across research studies regarding what adolescent peer crowds signify. Researchers in general tend to agree that adolescent peer crowd affiliation represents the tendency of adolescents “to place themselves and others into consensually recognized and labeled social types” (Sussman et al. 2007, p. 1). Undoubtedly, adolescent peer crowd affiliation represents a phenomenon involving a complex interplay among different types of self- and other-related social perceptions such as adolescents’ perceptions of themselves, their perceptions of what their peers perceive them to be, their peers’ actual perceptions of them, and how they would want their peers to perceive them. The diverse approaches taken to conceptualize and operationalize peer crowd affiliation in the current literature attest to the complexity of the peer crowd phenomenon. However, as illustrated by Sussman et al. (2007), the convergence of findings related to peer crowd names and characteristics across a methodologically varying set of studies suggests a general consensus among researchers regarding the nature of the peer crowd construct itself. That said, we do agree that more future research is needed to better understand the factors that influence adolescent crowd membership and the extent to which peer social network overlaps with peer crowd affiliation. We find Cross and Fletcher’s (2009) concern for sensitivity and specificity an important one. Although they don’t identify a method that might strike the right balance between specificity and sensitivity, we would welcome an advance in this direction. However, it should be noted that researchers have taken some precautions to increase the sensitivity and specificity of their measures. For example, in a self-identification measure an open-ended option is usually included for subjects to report the crowd names that do not appear on the provided list of names (Sussman et al. 2000, 2004). We agree with Cross and Fletcher (2009) that adolescents’ identification with multiple groups poses a common methodological problem in the study of peer crowds. More research that examines multiple crowd identification is needed. Also, more research is needed to determine the relative impact of each crowd on the behavior of adolescents who identify with multiple groups. This is a different sort of research question, of course, from asking youth to indicate the crowd about which they most closely identify. We feel that both types of research have value.