Brokers or Bridges? Exploring Structural Holes in a Crowdsourcing System

A method to measure the contributions of crowdsourcing participants identifies how roles relate to an incident's investigation and discussion. Using data on the South China tiger incident, the authors evaluate the performance of brokers--those who connect separate groups within a platform and across platforms--and show how results compare with structural hole theory. The supplemental material at http://personal.cityu.edu.hk/~qingzhang4/hfs-computer2016/Supplement.pdf includes additional information about source data.