Project-based knowledge work is characterised by decentralised and dynamic team-based structures, different from the tradi­tional, bureaucratic organisation. Arguably, this flexible and collaborative work setting could benefit from enterprise social media, which helps facilitate how people connect, collaborate and share information across organisational boundaries.

This thesis applies the theoretical lens of activity theory to explore the adoption, use and integration of enterprise social media in project-based knowledge work. Moreover, it develops a rich sociocultural understanding of how these platforms are situated in work activities. In particular, the focus lies on information sharing and the potential to connect different types of work, roles and responsibilities.

Through a qualitative research design, this thesis contributes towards under­standing the subtle interplay between enterprise social media, employees’ infor­mation sharing and their situated work activities. Key findings reveal that enter­prise social media created long-term strategic benefits, such as a shared knowledge base, situation awareness, horizon scanning, as well as making project-based knowledge work more intertwined. Furthermore, support was also found for a grassroots approach for adoption, as employees were personally invested and more likely to find meaningful use in their activities, through exploration, innovation and trial and error.

This thesis also identifies contradictions that relate to the role of enterprise social media for information sharing. It became evident that different platforms could co-exist in functional arrangements, with a specific place and purpose in the wider ecology. However, contradictions emerge in terms of overlaps between technolo-gies, asymmetry in usage and the appearance of different information sharing practices and dependencies.

This work presents new theoretical insights into how enterprise social media are used for information sharing in work activities, bringing attention to what people are aiming to achieve, and highlighting how sociocultural elements can have an influence.