Collaborative ontology engineering: a survey <s> DILIGENT <s> Purpose – Aims to present the ontology engineering methodology DILIGENT, a methodology focussing on the evolution of ontologies instead of the initial design, thus recognizing that knowledge is a tangible and moving target. Design/methodology/approach – First describes the methodology as a whole, then detailing one of the five main steps of DILIGENT. The second part describes case studies, either already performed or planned, and what we learned (or expect to learn) from them. Findings – With the case studies it was discovered the strengths and weaknesses of DILIGENT. During the evolution of ontologies, arguments need to be exchanged about the suggested changes. Identifies those kind of arguments which work best for the discussion of ontology changes. Research implications – DILIGENT recognizes ontology engineering methodologies like OnToKnowledge or Methontology as proven useful for the initial design, but expands them with its strong focus on the user-centric further development of the ontology and the provided integration of automatic agents in the process of ontology evolution. Practical implications – With DILIGENT the experience distilled from a number of case studies and this offers the knowledge manager a methodology to work in an ever-changing environment. Originality/value – DILIGENT is the first methodology to put focus not on the initial development of the ontology, but on the user and his usage of the ontology, and on the changes introduced by the user. We take the user’s own view seriously and enable feedback towards the evolution of the ontology, stressing the ontology’s role as a shared conceptualisation. <s> BIB001 </s> Collaborative ontology engineering: a survey <s> DILIGENT <s> The Diligent argumentation framework helps capture design deliberations in ontology-engineering discussions. It makes consensus-building tasks more efficient and provides detailed guidance for nonexperts. The semantic Web envisions an infrastructure in which humans and machines seamlessly exchange information on the Web. During the discussions participants raise new issues or elaborate on existing ones. Once a discussion evolves, participants can group issues and act on them accordingly. <s> BIB002
DILIGENT BIB001 proposes a methodology for collaborative ontology engineering based on the IBIS argumentation model  . The process model is divided into several phases to be carried out in multiple iterations: Build: A core team of domain experts, users, knowledge engineers and ontology engineers build an ontology that is not required to be complete as with respect to the requirements to be fulfilled. Local adaptation: The ontology is made available and users adapt it to their own needs in their local environments. However, the 'original' ontology remains unchanged while local adaptions are logged for future analysis. Analysis: Local branches of the shared ontology are analyzed with respect to their mutual differences and an ontology engineering board selects changes to be carried over into the next version of the shared ontology. Revision: The changes agreed in the previous phase are implemented in the shared ontology and a new version thereof is released. Local updates: Users may decide to align their local ontologies with the new version of the ontology released by the board in order to ensure compliance to commonly agreed standards, as well as communication and interoperability benefits arising from the usage of an ontology that is shared within the community. An overview of the methodology is presented in Figure 2 (see BIB002 . 