About

RESTful Grounding was the very first Web Ontology to allow the semantic description of RESTful Web Services. It was authored by two Brazilian researches, from the University of Sao Paulo (USP), Engineering School, as part of their master thesis on RESTful Semantic Web Services:

• Otavio F. Ferreira Filho (@otaviofff)
• Maria Alice G. V. Ferreira

Abstract

The proposal is to allow the development of semantic Web services according to an architectural style called REST. More specifically, it considers a REST implementation based on the HTTP protocol, resulting in RESTful Semantic Web Services.

The development of semantic Web services has been the subject of various academic papers. However, the predominant effort considers Web services designed according to another architectural style named RPC, mainly through the SOAP protocol. The RPC approach, strongly stimulated by the enterprise software industry, aggregates unnecessary processing and definitions that make Web services more complex than desired. Therefore, services end up being not as scalable or fast as possible.

In fact, REST services form the majority of Web services currently developed on the social Web, an environment focused on user-generated content and networking, clearly stronger and more predominant than others.

The proposal presented here makes use of a specific selection of existing languages and protocols, reinforcing its feasibility. First, OWL-S is used as the base ontology for services. Second, WADL is used for syntactically describing them. Third, the HTTP protocol is used for transferring messages; defining the action to be executed; and also defining the execution scope. Finally, URI identifiers are responsible for specifying the service interface.

The final compilation results in an ontology named RESTful Grounding, which extends OWL-S.

Code

The formal RESTful Grounding ontology definition, in the OWL format, can be found here:

• restful-grounding.owl

Rationale

Do we really need this? Get to know what Tim Berners-Lee, the inventor of the Web, feels about it. Get to know the rationale behind RESTful Semantic Web Services.

Paper

English Version

• Semantic Web Services: A RESTful Approach
• Proceedings of IADIS International Conference WWW/Internet (ICWI)
• 2009, Rome, pp. 169-180
• Presentation

Portuguese Version

• Serviços Semânticos: Uma Abordagem RESTful
• Proceedings of IADIS Iberian-American Conference WWW/Internet (CIAWI)
• 2009, Madrid, pp. 35-46
• Presentation

Example

Yahoo’s News Search (YNS) is a RESTful service that allows you to search the Internet for news stories. It queries a wide range of web portals simultaneously, including BBC, CNN, and Yahoo itself. Unfortunately, this web service hasn’t been described formally yet, which prevents semantic software agents from discovering, selecting, and invoking it without human assistance.

In order to overcome these limitations, both syntactic and semantic descriptions ought to be provided; a task accomplished by the files listed below.

Syntactic Description

• yns.wadl (Originally created by Marc Hadley)

Semantic Description

• yns-service.owl
• yns-profile.owl
• yns-process.owl
• yns-grounding.owl (RESTful Grounding ontology applied)