Abstract
This introduction to the special issue describes hidden organizations, offers several reasons for the lack of research on these collectives, and explains how this collection of articles helps move us forward in efforts to empirically study hidden organizations. After providing background information on the history of this special issue, the five articles published here are described in terms of the type of collective examined, the theories and methods used, and the key research questions addressed. Three observations about the published pieces are made: being hidden requires communicative effort; hiddenness is usefully understood in terms of identity management; and any discussion of hidden organizations raises ethical considerations. The piece closes with acknowledgements and a call for continued conceptual/theoretical and empirical research into hidden organizations.