Pano Maria, Victor Louwerse, John Walker


Enabling Intelligent SKOS API Clients

SKOS is a widely adopted W3C recommendation. It provides us with a standard way of expressing and exchanging concept schemes like taxonomies and thesauri. SKOS concept schemes are often managed in tools that provide a user-friendly way of managing these. Such tools typically have proprietary features, such as workflows, user management, audit trails, etc.
To enable machine interaction, most tools expose a proprietary web API. Unlike the data itself, which adhere to SKOS, these APIs do not adhere to a standard interface. This necessitates the creation of custom client software for machine interaction with each SKOS tool.
Based on recent developments in the semantic description of web APIs, a method of intelligent interaction between a SKOS client and API is proposed. This approach provides a way for machine clients to discover possible operations that the SKOS tool exposes at run-time, enabling the machine client to intelligently handle tasks. This allows for the creation of a generic intelligent SKOS client which can interact with multiple SKOS APIs.

With the rapid rise of semantic web technology, there is an increasing demand for the implementation of SKOS tools. As semantic web consultants, we are often required to migrate data from existing sources to some chosen SKOS environment. In order to leverage the capabilities of these tools, the specific tool’s API is used to automate tasks such as concept creation and organization. Working with multiple tools, the frustration of using different APIs to perform exactly the same tasks arises.
In this talk we introduce our approach to creating a client that can intelligently interact with SKOS web APIs. We introduce a SKOS API metamodel which describes the necessary SKOS resources and their properties, as well as the possible actions that can be performed on these.
We discuss the approach the intelligent client application must take to perform a requested task, how the client is able to discover the affordances that the SKOS API provides, and how it can interpret these and orchestrate the necessary actions to complete the task. Not every API is the same, and not all APIs will support all possible actions that the SKOS API metamodel enables. Therefore the client must be resilient and flexible.
We discuss how APIs must provide an RDF description which expresses how its operations implement the SKOS API metamodel, and which resources represent these, and how one can effectively create one if the API fails to do so.
Finally, we present the working SKOS API metamodel that we developed, and demonstrate our intelligent SKOS client as it interacts with a SKOS API of a SKOS tool implementation.


Pano Maria is specialized in information modeling and architecture, and has a keen interest in standards based semantic technologies. The recent uptake of these technologies in various industries is an exciting development that Pano actively follows and participates in, for example through several W3C groups. Moreover, he contributes to open source software development that pushes the development of the semantic web forward. As an information architect at Taxonic, he helps organizations develop and implement their semantic web and linked data strategies. In his most recent projects at the Dutch Cadastre, and the Dutch National Police he works on semantic modeling and transformation of source data to linked data.

Victor Louwerse has a background in computer science. During his studies, he developed a passion for machine learning and artificial intelligence techniques. For several years, he applied these techniques as an entrepreneur, and later on as a self-employed game developer.
With an interest towards all aspects of information technology, Linked Data technology eventually caught his eye. Since, even after all these years, Java has not lost its charm for Victor, he continues to practice Java (and cousins) in a Linked Data context, as a senior consultant at Taxonic. As his interest in science has not waned, an important aspect of his work is continuous innovation and thinking outside established frames.

John Walker is co-founder and director of Semaku. Encompassing content management, product information management and product lifecycle management, Semaku helps clients to streamline and implement the big picture with a unified approach. John is passionate about bringing the benefits linked data and semantic technologies into the enterprise world. Clients include NXP, Nexperia, Philips, Kadaster, Vebego, Lekkerland. John is originally from the United Kingdom where he studied Computer Science and Mathematics at the University of York. In 2000 John moved to the Netherlands where he continues to live with his partner and son. In his free time, John enjoys riding his motorcycle, watching live music (especially Iron Maiden) and playing bass guitar.