This document summarizes a study on using learning analytics to foster metacognition and formative assessment in collaborative writing. The study developed a prototype called Uatu that surfaced real-time writing activity data from Google Docs. Researchers conducted a case study with 8 students over 15 weeks, collecting observation, interview, and artifact data. Key findings included how collocation, ephemeral contributions, and different types of "writing" impacted collaboration and assessment of contributions. The prototype was most useful for distributed/online contexts with ongoing multi-author work.