Most of the current methodologies for building ontologies rely on specialized knowledge engineers. This is in contrast to real-world settings, where the need for maintenance of domain specific ontologies emerges in the daily work of users. But in order to allow for participatory ontology engineering, we need to have a more realistic conceptual model of how ontologies develop in the real world. We introduce the ontology maturing processes which is based on the insight that ontology engineering is a collaborative informal learning process and for which we analyze characteristic evolution steps and triggers that have users engage in ontology engineering within their everyday work processes.

This model integrates tagging and folksonomies with formal ontologies and shows maturing pathways between them. As implementations of this model, we present two case studies and the corresponding tools. The first is about image-based ontology engineering (introducing so-called imagenotions), the second about ontology-enabled social bookmarking (SOBOLEO). Both of them are inspired by lightweight Web 2.0 approaches and allow for realtime collaboration.

Within state-of-the-art semantic approaches, ontologies have emerged as the key to enable more advanced technological support for end users and their work processes, which particularly applies to knowledge work. However, current research and development concentrates more on what we can do as soon as we have ontologies—rather than having a closer look at the processes of creating and especially maintaining such domain-specific ontologies. In real-world settings these issues are crucial to fulfill the users’ needs and currently insufficiently dealt with.

It is usually acknowledged that ontologies are shared understandings of a particular domain that have to be constructed within social processes among the stakeholders. However, current methods and tools do not empower the users to actually carry out these negotiation processes embedded in their work.

This is mainly due to lopsided and partially naive perspectives on ontology engineering. One perspective requires ontology engineering experts who moderate the ontology creation processes and on whom users will depend indefinitely.

In the other perspective, it is assumed that users become ontology modeling experts right away. Presupposing an ontology engineering expert, we have to face two problems:
First, involving ontology engineering specialists is expensive and second, ontologies produced by modeling experts instead of domain experts can contain errors caused by the insufficient domain knowledge and experience of knowledge engineers [2]. Leaving the complete, challenging and complex task of ontology modeling to the domain experts on theother hand is usually not an option either! Often users are not motivated to invest the effort because they are concerned with their work processes and regard ontology modeling in its traditional form as an overhead. The main reason therefore is the fact that the time lag between the emergence of concepts and their inclusion in ontologies is far too big for ontologies to be useful [14]: concepts are already becoming obsolete by the time they are entering the ontology.

Indeed, users are almost constantly constructing and negotiating shared meaning in collaboration with others by augmenting and evolving a community vocabulary. The main challenge is then how to leverage this implicit and informal ontology building for the explicit formal models needed for semantic approaches. What we actually need in order to cope with this challenge are two things: First, on the conceptual level: a more realistic and work-integrated view of how ontologies actually are or can be created and second, on the technical level: tools supporting interweaving working and ontology engineering activities and the associated social negotiation process.

Download pdf Ontology Maturing: a Collaborative Web 2.0 Approach to Ontology Engineering