Published on in Vol 20, No 5 (2018): May
Preprints (earlier versions) of this paper are
available at
https://preprints.jmir.org/preprint/9683, first published
.
1 IWM Leibniz-Institut für Wissensmedien (Knowledge Media Research Center), Knowledge Construction Lab, Tübingen, Germany
2 L3S Research Center, Leibniz University of Hannover, Hannover, Germany