The *ACM 2012 Conference on Computer Supported Cooperative Work* (http://cscw2012.org) is a premier venue for presenting research in the design and use of technologies that affect groups, organizations, and communities. CSCW encompasses both the technical and social challenges encountered when supporting collaboration. The development and application of new technologies continues to enable new ways of working together and coordinating activities. Although work is an area of focus, CSCW embraces research and technologies supporting a wide range of recreational and social activities using a diverse range of devices. The conference brings together top researchers and practitioners from academia and industry who are interested in both technical and social aspects of collaboration. CSCW 2012 will be held February 11-15, 2012, in Seattle, Washington, USA. A record number of Papers & Notes were submitted to CSCW 2012 in June. The Papers & Notes track is now closed, and we want to encourage CSCW researchers and practitioners -- including those who submitted Papers & Notes -- to submit contributions to one or more of the following open tracks, all of which have an deadline of *September 9, 2011*, 5:00pm PDT: /CSCW Horizon/, /Demonstrations/, /Interactive Posters/, /Panels/, /Videos/ and /Student Volunteers/ (http://cscw2012.org/participation.php). The Interactive Posters and Demos Reception on the first evening of the main conference represents an often under-appreciated opportunity for participants to make valuable connections with other researchers and learn what they find interesting or unclear about your work, get pointers to related work, and forge relationships that may lead to potential new paths, collaborations and/or future external letters of reference. Unlike most other tracks, where the number of accepted submissions is limited by available time in the program, we have ample space for a large number of Posters and Demos, and are hoping a record number of participants will help fill it with engaging people, ideas and conversations. *CSCW Horizon * (http://cscw2012.org/participation/horizon.php) CSCW Horizon provides an opportunity to showcase and discuss research that expands the boundaries of CSCW beyond its standard topics and approaches. We solicit creative, unorthodox, inspirational submissions that help advance the CSCW community constructively, by provoking debate, predicting beyond the research horizon, or revealing unresolved issues in the field. This can be a chance for authors to present work that: * Challenges the basdic questions being asked and approaches used in traditional CSCW work * Brings new perspectives from other fields * Is visionary, futuristic, or has not been previously explored * Is generally less represented at the conference * Is controversial * Could benefit from public discussion that would not be possible in a traditional session. *Demonstrations* (http://cscw2012.org/participation/demos.php) CSCW 2012 demonstrations present implementations of new CSCW systems and concepts. The peer-reviewed demonstrations allow conference participants to view novel and noteworthy CSCW systems in action, discuss the systems with those who created them, and try them out. Appropriate demonstrations include applications, technologies, and research prototypes, and may include work that has been previous published at CSCW or elsewhere. Demonstrations can also serve to showcase novel commercial products not previously described in the research literature. Demonstrations should be interactive and provide attendees a hands-on experience. The demo forum is not an opportunity for marketing or sales presentations. Presenters must have been directly involved with the development of the system and be able to explain the unique and novel contributions of the system. *Interactive Posters* (http://cscw2012.org/participation/posters.php) CSCW 2012 will include an interactive poster category for late-breaking and preliminary results, smaller results not suitable for a full or short paper, innovative ideas not yet validated through user studies, early student research, and other research best presented in an interactive forum. Posters will be presented in a special Poster Session where researchers will interact directly with conference attendees. The posters will then remain up throughout the remainder of the conference. Accepted Interactive Poster abstracts will be published in ACM Digital Library and distributed to conference attendees as part of the Conference Extended Abstracts *Panels* (http://cscw2012.org/participation/panels.php) Panels are a great way to generate debate and raise new and interesting issues at CSCW. With panels we want to provide a forum for discussing provocative, controversial, innovative, emerging, boundary-spanning and boundary-breaking issues. The best panels provide opportunities for audience participation. We especially encourage innovative formats that will engage the audience, that address critical and contemporary topics, and that engage multiple disciplines in productive dialog. Is a panel a kind of cooperative work that can benefit from some kind of computer support? Or not? While paper sessions provide detailed discussions of work recently completed, panels provide an opportunity to explore what is on the horizon --- or what is already here but not adequately recognized, acknowledged or discussed. *Videos* (http://cscw2012.org/participation/videos.php) The CSCW Videos provides researchers with opportunities to present their cutting-edge work in an interactive fashion in front of an expert audience. Videos are ideally suited to demonstrate the practical application of research results and the functionality of CSCW systems, visualize the outcome of research and development projects, or describe inspiring visions of future systems that are grounded in today's reality. The Videos Program provides a venue to present work that involves dynamic interaction, ranging from demonstrations of new systems to complex aspects of group communication and work practice. CSCW 2012 will accept both standalone full videos and video figures which illustrate papers in the Papers and Notes programs. Potential topics include, but definitely are not limited to: * demonstrations of innovative research prototypes * demonstrations of innovative aspects of commercial systems * studies of work practice that have implications for CSCW * retrospective collections of significant CSCW fields of work * visions of future technologies *Student Volunteers* (http://cscw2012.org/participation/sv.php) Student volunteers are essential to the success of the CSCW conference. In return for help at the conference, student volunteers receive a number of benefits including: * free conference registration * a fabulous t-shirt sure to be the envy of all conference goers * a complimentary Conference Reception ticket The complete Call for Participation, including more information about CSCW Horizon, Demonstrations, Interative Posters, Panels, Videos and Student Volunteers can be found on the CSCW 2012 web site (http://cscw2012.org/participation.php). You can also follow announcements about the conference on Twitter (http://twitter.com/ACM_CSCW2012), and/or "like" us on Facebook (http://www.facebook.com/CSCW2012). We look forward to your participation! -- *The 2012 ACM Conference on Computer Supported Cooperative Work* 11-15 February 2012 Seattle, Washington, USA /Homepage/: cscw2012.org <http://cscw2012.org> /Twitter/: @ACM_CSCW2012 <http://twitter.com/acm_cscw2012> /Facebook/: www.facebook.com/CSCW2012 <http://www.facebook.com/CSCW2012>