LexiTags: An Interlingua for the Social Semantic Web Csaba Veres University in Bergen, Fosswinckelsgt. 6, 5020 Bergen, Norway. Csaba.Veres@infomedia.uib.no Abstract. The paper describes lexitags, a new approach to social semantic tagging whose goal is to allow users to easily enrich resources with semantic metadata from WordNet. This is a paradigm example of the Social Web and the Semantic Web working together: ordinary users help create the metadata so needed by the Semantic Web and in turn, Semantic Web technologies help those users get a richer experience from the Social Web. A family of simple user interfaces for lexitagging is described, as are some methods for the subsequent, automatic generation of lightweight ontologies. These ontologies are presented as an ideal interlingua for the Social Semantic Web. Keywords: Social Web, Semantic Web, ontology, metadata, WordNet, linked data, rdf, folksonomy 1. Introduction Two of the most exciting innovations for transforming the World Wide Web are “Web2.0” [1] and the “Semantic Web”. Each has a separate vision for moving a relatively static Internet driven by focused content providers, to a dynamic and largely self managing entity enabled by large volumes of metadata. But while the general vision is shared, the details of the two approaches appear to be opposites. While Web2.0 is focused on free-form, user generated ad hoc metadata and opportunistic social organization, the Semantic Web is a vision containing strict and enforced data structures suitable for automated machine processing. Web2.0 has proven advantages in the ease of data creation and a correspondingly lower threshold for user adoption, but the lack of predefined structure may inhibit effective retrieval as the amount of unstructured metadata grows in volume. An obvious idea is to combine the two sets of technologies so that the users can have systems which behave as Web2.0 at the point of insertion, yet as Semantic Web at the point of retrieval. Following papers such as [2], it is now widely agreed in the community that the Semantic Web and the Social Web can benefit from each other. In particular, the Information Architecture community has embraced folksonomy 1 as a way to enhance information management practices. An analogy is often made with the term desire lines, which comes from landscape architecture. The basic idea originates in the observation that, in spite of the careful planning undertaken by architects to lay out walking tracks in their meticulously designed spaces, one will often find emergent paths that have been forged by people who deviate off the planned tracks onto the grass or gravel of the spaces. The paths become entrenched when particular tracks are found useful by many people. It is similar in information spaces, where folskonomy describes the desire lines, representing informal tag based classification schemes that people find useful. The addition of formalized “desire lines” on the web would benefit emerging semantic platforms that rely on such metadata, especially with respect to querying and mining social semantic data. This paper describes a set of tools and principles currently under development, which will help formalize folksonomy for the web. In the next section we describe some of the main problems with current tagging practice. Then we describe our approach to cleaning up tags and generating formal rdf based semantic tags. Following this, a method for automatically generating lightweight ontologies from semantic tags is described, and their use as a universal interlingua is 1 http://vanderwal.net/folksonomy.html