Sunday, September 27, 2009

Watson - An efficient access point to online ontologies - A gateway to the Semantic Web

Next generation semantic applications will be characterized by a large number of sometimes widely-distributed ontologies, some of them constantly evolving. That is, many next-generation semantic applications will rely on ontologies embedded in a network of already existing ontologies. Other semantic applications – e.g. some electronic health records (EHR) – will maintain a single, globally consistent semantic model that serves the needs of application developers and fully integrates a number of pre-existing ontologies.

As the Semantic Web gains momentum, more and more semantic data is becoming available online. Semantic Web applications need an efficient access point to this Semantic Web data. Watson, the main focus of this post, provides such a gateway. Two limited demonstrations of Watson - one video, the other static - are given below.

Overview of Watson Functionalities

The role of a gateway to the Semantic Web is to provide an efficient access point to online ontologies and semantic data. Therefore, such a gateway plays three main roles:

(1) it collects the available semantic content on the Web
(2) analyzes it to extract useful metadata and indexes, and
(3) implements efficient query facilities to access the data.

Watson provides a variety of access mechanisms, both for human users and software programs. The combination of mechanisms for searching semantic documents (keyword search), retrieving metadata about these documents and querying their content (e.g., through SPARQL) provides all the necessary elements for applications to select and exploit online semantic resources in a lightweight fashion, without having to download the corresponding ontologies.

For a easy-to-follow video demonstration of The Watson plug-in for the NeOn toolkit, click on

and, better still, click one of the Media Player links at this destination.

Note: There is a Watson plug-in for the ontology editor Protégé in the works.

Protégé (see my August 24 post below) is probably the most popular ontology editor available. In addition, its well established plug-in system facilitates the development of a plug-in using the Waston Web Services and API. To date, however, the Protégé site provides only what it describes as, “more a proof of concept or an example than a real plug-in.”

NeOn Toolkit

The NeOn architechture for ontology management supports the next generation semantics-based applications. The NeOn architecture is designed in an open and modular way and includes infrastructure services such as a registry and a repository and supports distributed components for ontology development, reasoning and collaboration in networked environments.

The NeOn toolkit, the reference implementation of the NeOn architechture, is based on the Eclipse infrastructure.

Ontology Management
Semantic Web, Semantic Web Services, and Business Applications
Copyright 2008 Springer

A static demonstration of the Watson plug-in for the NeOn toolkit

The Watson plug-in allows the user to select entities of the currently edited ontology he/she would like to inspect, and to automatically trigger queries to Watson, as a remote Web service. Results of these queries, i.e. semantic descriptions of the selected entities in online ontologies, are displayed in an additional view allowing further interactions. The figure below provides an example, where the user has selected the concept “human” and triggered a Watson search. The view on the right provides the query results (a list of definitions of class human which have been found on the Semantic Web) and allows easy integration of the results by simply clicking on one of the different “add”-buttons.

Finally, the core of the plug-in is the component that interacts with the core of the NeOn toolkit: its datamodel. Statements retrieved by Watson from external ontologies can be integrated in the edited ontology, requiring for the plug-in to extend this ontology through the NeOn toolkit datamodel and data management component.

{click on the image above for a larger view}

An interesting exercise:
And search on "snomed"

And, this dynamic view is what you get after clicking the (view as graph) link.