The nature of the available information and its role in our lives have changed significantly, but the methods and tools that are used to access and share that information in collaboration have remained largely unaltered. Within the GROUP/CSCW community, the area of collaborative information seeking/retrieval/behavior (CIS/CIR/CIB) has drawn a new stream of interest to it in the recent years. This has been possible due to involvement and initiatives of several prominent researchers from various fields, such as IR, HCI, LIS, and CSCW. This workshop is aimed to take these efforts to the next level by focusing on theories and models that are grounded in the literature and existing empirical studies, as well as applications and tools that help us advance the field further. We are interested in bringing together a group of researchers working on various conceptual and technical aspects of collaborative information seeking, search, retrieval, and sensemaking. The workshop will provide an excellent opportunity to share your work-in-progress, seek valuable feedback from your fellow researchers, and start or strengthen collaborative endeavors.