U. Gadiraju, S. Möller, M. Nöllenburg, D. Saupe, S. Egger-Lamperl, D. Archambault, and B. Fisher. volume Evaluation in the Crowd. Crowdsourcing and Human-Centered Experiments. Dagstuhl Seminar 15481, Dagstuhl Castle, Germany, November 22 – 27, 2015, Revised Contributions of Information Systems and Applications, incl. Internet/Web, and HCI, page 6-26. Springer International Publishing, (2017)