Crowdtruth: Machine-human computation framework for harnessing disagreement in gathering annotated data

Abstract

In this paper we introduce the CrowdTruth open-source software framework for machine-human computation, that implements a novel approach to gathering human annotation data for a variety of media (e.g. text, image, video). The CrowdTruth approach embodied in the software captures human semantics through a pipeline of four processes: a) combining various machine processing of media in order to better understand the input content and optimize its suitability for micro-tasks, thus optimize the time and cost of the crowdsourcing process; b) providing reusable human-computing task templates to collect the maximum diversity in the human interpretation, thus collect richer human semantics; c) implementing ’disagreement metrics’, i.e. CrowdTruth metrics, to support deep analysis of the quality and semantics of the crowdsourcing data; and d) providing an interface to support data and results visualization. Instead of the traditional inter-annotator agreement, we use their disagreement as a useful signal to evaluate the data quality, ambiguity and vagueness. We demonstrate the applicability and robustness of this approach to a variety of problems across multiple domains. Moreover, we show the advantages of using open standards and the extensibility of the framework with new data modalities and annotation tasks.