Traditional IR techniques, systems, and methods that assume an individual searcher are often shown to be inadequate for addressing search problems that are multi-faceted and/or too complex or difficult for individuals. The next big leap in information seeking/retrieval could happen by considering social and collaborative aspects of search. In this half-day tutorial, this concept, along with some of the foundational works and latest developments in the field of collaborative information seeking (CIS) will be presented. Specifically, the course will introduce the student to theories, methodologies, and tools that focus on information retrieval/seeking in collaboration. The student will have an opportunity to learn about the social aspect of IR with a focus on collaborative search or CIS situations, systems, and evaluation techniques. The three hours will be divided as: (1) introduction to group-based IR models, approaches, and systems; (2) back-end of CIS systems with system-focused mediation and front-end with user-focused mediation; and (3) evaluation of CIS systems/approaches, prediction and recommendations with collaborative aspects of IR, and future directions. The attendees will be given a course-pack that will include a reference list, an annotated bibliography of seminal works in the field, and depictions of relevant models/frameworks.