Building ontologies is a collaborative process: the ontology should represent the community's view on the respective domain. To achieve this, the community must be given the appropriate environment to facilitate discussion, consensus finding, and to come up with a final ontology. Several methods for collaborative ontology engineering exist, as well as approaches to support argumentation in this task. The thesis will provide an overview of these methods. Next, it will re-use, adapt, and implement an argumentation framework for the Semantic MediaWiki Vocabulary Editor. The work will be evaluated in several real world scenarios in a European project. Students should have attended courses on semantic technologies, have an interest in socio-technological problems, in Web 2.0 technologies, and strong skills in written English.