An electronic advice network provides employees opportunities to tap diverse experts within the organization at an unprecedented speed and scale. It is formed when an advice seeker initiates an online discussion thread joined by members of various communities, each specializing in a specific domain. This dissertation recognizes the substantial gap in our understanding of how to best harness the performance potential of expertise diversity provided through an electronic advice network within a firm. It thus investigates the process by and conditions under which expertise diversity in an electronic advice network promotes the advice seeker’s learning and performance. A field study was conducted via multi-methods including observation, interviews, and survey at a global company running discussion forums spanning internal virtual communities. The unit of analysis was at the discussion thread level. 190 discussion threads comprising 1,200 participants and associated outcomes (rated by their respective advice seekers) were analyzed. Findings suggest that, for the seeker to realize the performance potential of diverse inputs, discussion participants should facilitate the seeker’s learning by engaging in collective elaboration—articulating the differences and relevance of their diverse inputs. The seeker learned and performed the least when discussion participants were highly diverse but did not engage in collective elaboration. Discussion participants engaged in collective elaboration to the extent that they had previously established shared syntactic and semantic understanding of each other’s expertise domains through participation in each other’s communities. This dissertation contributes to the virtual communities literature by unearthing the relationships between expertise diversity and the advice seeker’s learning and performance and explaining when and how the seeker benefits from the diverse knowledge shared through an electronic advice network. The moderating role of collective elaboration explains why prior research may have found no or even a negative relationship between expertise diversity and discussion outcomes. It also contributes to the team literature by offering boundary conditions for the previous findings on expertise diversity and common ground. The collective elaboration construct can be also adopted by team diversity researchers to better understand where a disruption in the chain of group-level information processing may occur in some diverse teams. / text