Before revision: We consider crowdsourced labeling under a  worker-task specialization block model, where each worker and task is associated with one particular type among a finite set of types and a worker provides a more reliable answer to tasks of the matched type than to the tasks of unmatched types.
After revision: We consider crowdsourced labeling under a worker-task specialization model, where each worker and task is associated with one particular type among a finite set of types and a worker provides a more reliable answer to tasks of the matched type than to the tasks of unmatched types.