Systems and methods of crowd sourcing by distributing a task over a network to multiple workers for completion while providing quality control are disclosed. In one aspect, embodiments of the present disclosure include a method, which may be implemented on a system, of identifying an attribute of the task, the task including multiple unit jobs, determining target accuracy in completion of the task by the multiple workers, computing a number of results to be collected for a unit job of the task based on the target accuracy, setting a wage amount that is offered to a worker for completing a unit job of the task based on the attribute and the target accuracy, and/or collecting and aggregating statistics of the workers completing the select unit jobs for quality control.