  Before contributing new knowledge, individuals must attain requisite
background knowledge or skills through schooling, training, practice, and
experience. Given limited time, individuals often choose either to focus on few
areas, where they build deep expertise, or to delve less deeply and distribute
their attention and efforts across several areas. In this paper we measure the
relationship between the narrowness of focus and the quality of contribution
across a range of both traditional and recent knowledge sharing media,
including scholarly articles, patents, Wikipedia, and online question and
answer forums. Across all systems, we observe a small but significant positive
correlation between focus and quality.
