This chapter presents different approaches to describe the shape and characteristics of groups and collectives in the sciences, the humanities, and the arts. The conceptualizations introduced are thought collective and thought style (L. Fleck); academic tribes and territories (T. Becher, P. Trowler); epistemic culture (K. Knorr Cetina); the scientific community (W. Hagstrom); the invisible college (D. Crane); the scientific school (E. Tiryakian); the collaborative circle (M. Farrell); the epistemic community (P. Haas); and the scientific/intellectual movement (S. Frickel & N. Gross). These considerations pave the way for the theoretical framework and the related research design used in the studies described in this book.