There is no doubt that the Web provides a potential platform for global access to information, but there are a number of important issues that need to be addressed for this potential to be fully achieved. The Web was not initially envisioned as a tool for global access to information, and the underlying standards for information management are not entirely adequate. By the very nature of the Internet's architecture, information on similar subjects is scattered across many different servers around the world, yet there are few tools to integrate related information from different sources. As a result, it is often very difficult to find things on the Web.
Such problems can only be solved if action is taken to establish appropriate norms, vocabularies, guidelines and standards to facilitate the integration of data from different sources, and to engage in effective data exchange. Through the adoption of international classification schemes, controlled vocabularies, open standards, and common data models we will eventually overcome many of the information management problems of the Internet; through the development of tools that exploit such standards it will ultimately be possible to provide an effective framework for "one-stop shopping", where people can search for agricultural information resources in one place, without having to explore many different individual Web sites.
In the agricultural sector there exist already many well-established and authoritative controlled vocabularies, such as FAO's AGROVOC Multilingual Thesaurus, the CAB Thesaurus, and the thesaurus of the National Agricultural Library in the United States. However, for these semantic tools to be entirely effective on the Internet, there is a need to re-assess the traditional "thesaurus" approach and move towards a more modern technique that better suits the Web environment, such as the development of "ontologies". Ontology is a concept that has been emerging from the various Semantic Web initiatives, which roughly speaking can be defined as a semantic system that contains terms, the definitions of those terms, and the specification of relationships among those terms.
One way to conceptualise an ontology is as an enhanced thesaurus-a thesaurus defined as a tool that fixes the vocabulary of a given subject area. Whether one wishes to describe a particular information resource or retrieve it from the Internet, one faces the same problem of what term or terms convey precise semantic information about the resource. For example, without the aid of a controlled vocabulary one may wonder whether to use the term "car," "automobile," or "vehicle" in performing a given search on the Internet. With a thesaurus, however, the searcher may be advised that "automobile" should be used instead of "car," and that "vehicle" is a broader term than "automobile" and therefore should be used in a different context. The degree to which terminology is semantically precise will have a direct impact on the degree to which relevant information can be found.
An ontology takes this conceptual framework one step further by structuring the terms more formally, and by providing richer relationships between concepts than what is currently provided in thesauri. Through the formal definition of terms, and a more precise description of relationships between terms, the user will be provided with a much richer contextual setting in which to make assessments of relevance and usage. At the same time, by more formally structuring the context and meaning of terms, ontologies become an integral part of the Semantic Web, described by Tim Berners-Lee as "an extension of the current Web in which information is given well-defined meaning, better enabling computers and people to work in co-operation."
In response to such a new approach to managing vocabularies, we have started the development of an Agricultural Ontology Service / Concept Server (AOS/CS). The AOS/CS project will function as a tool to help structure and standardize agricultural terminology in multiple languages for use by any number of different systems around the world.
The main objectives of the AOS/CS are to provide a framework for:
- better indexing of resources;
- better retrieval of resources; and
- increased interaction within the agricultural community.
With respect to the Semantic Web initiative, the AOS/CS would strive to:
- increase the efficiency and consistency with which multilingual agricultural resources are described and associated together;
- increase functionality and relevance in accessing these resources; and
- provide a framework for sharing common descriptions, definitions and relations within the agricultural community.
Once constructed, the AOS/CS will offer a contextually rich and modern framework for modelling, serving, and managing agricultural terminology. When integrated with Web-based search tools, it will greatly facilitate resource retrieval, not only providing access to the specific documents that a particular individual is looking for, but also offering suggestions for other related resources that are potentially relevant to the topic of interest. Such additional functionality will not only dramatically increase the scope of Web-based search engines, but will also revolutionize the way users interested in agricultural resources interact with the Web. The AOS will pay a strategic role in FAO's effort to fight hunger with information.
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