Document Type

Conference Paper


This item is available under a Creative Commons License for non-commercial use only


Computer Sciences

Publication Details

Machine Learning Meets Crowdsourcing Workshop in conjunction with International Conference on Machine Learning, Atlanta, Georgia, USA, 2013


Nowadays crowdsourcing is widely used in supervised machine learning to facilitate the collection of ratings for unlabelled training sets. In order to get good quality results it is worth rejecting results from noisy/unreliable raters, as soon as they are discovered. Many techniques for filtering unreliable raters rely on the presentation of training instances to the raters identified as most accurate to date. Early in the process, the true rater reliabilities are not known and unreliable raters may be used as a result. This paper explores improving the quality of ratings for train- ing instances by performing re-rating. The re-rating relies on the detection of such in- stances and the acquisition of additional ratings for them when the rating process is over. We compare different approaches to re-rating and compare the improvements in labeling accuracy and the labeling costs of these approaches.