Knowledge Space Lab: Design versus Emergence. Comparison between the structure and evolution of categories in the Wikipedia and the Universal Decimal Classification. 2009-2011.Background:This research has been conducted by the project "Knowledge Space Lab - mapping knowledge interactively" (OND 1337291}. Funded by the Royal Netherlands Academy of Arts and Sciences - KNAW, from September 2009 - March 2011 [Strategiefondsproject KNAW - Amsterdam - The Netherlands] the project contributed to the new research area of mapping and modelling of science. The project addressed the difference between representing scholarly knowledge in (external) classification systems (such as thesauri, ontologies, bibliographic systems) and 'internal' representations based on data- and user-tagging (such as network analysis, user annotations/tagging, folksonomies).