Consensus-based techniques for range-task resolution in crowdsourcing systems

In crowdsourcing, a range task is a type of creation task where only free answers belonging to the numeric domain are accepted/possible. In this paper, we present the median-on-agreement (ma) techniques based on statistical and consensus-based mechanisms for determining the result of range tasks. The ma techniques are characterized by i) the distinction between the group of workers that agree (i.e., workers in the consensus) on the task result from the group that disagree, and ii) the calculation of the final task answer through a median-based mechanism where only answers of workers in the consensus are considered.