Relevance & Research Question: Businesses are increasingly implementing Enterprise Social Software (ESS) for more efficient employee communication, improved knowledge sharing, increased productivity, and enhanced innovative abilities. Beginning with blogs and wikis in the early 2000s, ESS may now include any combination of tools for social networking, video conferencing, text messaging, or project management. However, common metrics and methods for the evaluation of the impact of ESS have yet to be established. Not only is the market for ESS diversified and ever-changing, business goals, work processes, and organizational structures differ from company to company. This results in varying evaluation metrics and methods in almost every case study. Executives need more guidance on the following question: Which metrics are suitable for ESS evaluation and what are the strengths and limitations of corresponding methods?

Methods & Data: The submission is based on five years of ongoing case study research on ESS in a public research institution. We gathered the data from ESS of three large German companies. Methods used are logfile analysis, network analysis, content analysis, genre analysis, standardized user web surveys, and in-depth interviews with stakeholders.

Results: While network statistics provide a wealth of detailed information on user activity, shared content, active project groups, and business relevant outcomes, they often lack context and may be difficult to interpret correctly. Standardized user surveys and in-depth interviews, on the other hand, provide a lot of context, but not enough raw data to justify business decisions. Therefore, we recommend a combination of methods within a mixed approach. This approach needs to be tailored to suit a business goals, work processes and organizational structures. Furthermore, it needs to be periodically evaluated and adjusted to the company's current requirements.

Added Value: The submission provides an overview of current mixed-methods research in ESS evaluation, adequate methods for several key metrics, as well as information on what the particular strengths and limitations of the different methods are. Company executives can choose metrics that are relevant to them and use the overview as a research-based guidance in selecting adequate methods for ESS evaluation.