Ivo Hristov, Gennady Agre, Danail Dochev. Measuring the Learning Progress in a "Learning by Authoring" Semantic Web Services based Ecosystem. In Alexander Verbraeck, Markus Helfert, José Cordeiro, Boris Shishkov, editors, CSEDU 2011 - Proceedings of the 3rd International Conference on Computer Supported Education, Volume 2, Noordwijkerhout, Netherlands, 6-8 May, 2011. pages 413-418, SciTePress, 2011.