Nowadays, social, economical, cultural, and technological changes deeply stress the professional profiles. As a consequence, everyone needs to be continually improving his/her professional skills by means of different kinds of continuing learning or lifelong learning. This changeable context also stresses the teachers’ job. Networking technologies can be useful in helping teachers to improve their skills anywhere (i.e., home, office, or school). However, the Web had grown up as a business space and has become an important repository of all kinds of information. As a result, searching information is a hard and slow process. Tools for data retrieval work at the syntactic level, disregarding the semantic aspects. Solutions show up to Web Semantic technologies. Our contribution is to develop a digital library for the e-learning specific domain using ontology-based semantic querying.
Technological changes are deeply stressing professional profiles and people need to continually improve their professional skills using different kinds of lifelong learning. Networking technologies became widely adopted to promote lifelong learning. However, searching information on the Web is a hard process. Current search engines were developed to work as productivity tools, helping users to retrieve data by means of information retrieval at the syntactic level, disregarding the semantics aspect. Words have different meanings depending on the context. The Web, on the other hand, is organized as an information network without any hierarchy or navigational contexts. Users often feel lost and cognitively overloaded, and they not always find the information they are searching for. Solutions point to the Semantic Web (Bernes-Lee, Handler, & Lassila, 2001) and a key point is the notion of ontology (Guarino, 1998).
Aiming to help lifelong learning initiatives and improve information search at the Web, we are developing a digital library for the e-learning domain which main service is a search engine that retrieves information by tracing the domain vocabulary met on ontology (Santos, Campos, & Braga, 2005). Our digital library extends the Web portal’s functionalities, providing technical information and communication and collaboration spaces, and hosts a wide variety of information (e.g., technical papers, Web sites of systems and tools, Web sites of Brazilian and international experience on e-learning, and some e-learning software artifacts to be used to create tailored e-learning applications). It provides services for cataloging, storing, searching, and retrieving information based on ontology-based semantic queries. The next sections argue domain ontology and e-learning ontology, describe the digital library, and offer the conclusions and future works.
Domain Ontology and e-learning Ontology
Ontology, in philosophy, refers to a conception of what can exist or “be” in the world. The artificial intelligence community has appropriated the term to mean the construction of knowledge models (Gruber, 1993), which specify concepts or objects, their attributes, and interrelationships. A knowledge model is a specification of a domain, or problem solving behavior, which abstracts from implementation-specific considerations and focuses instead on the concepts, relations, and reasoning steps in order to solve the problem (Shum, Motta, & Domingue, 2000).
Ontology specifies a shared understanding of a domain of interest and contains a set of concepts, together with its definitions and interrelationships, and possibly encodes a logical layer for inference and reasoning. The role of ontology is to reflect a community’s consensus on a useful way to conceptualize a particular domain. Building ontology implies acquiring the domain knowledge and collecting appropriate information resources that will define, with consensus and consistency, the terms used formally to describe the domain of study.
Ontology is beginning to be used in the context of digital libraries for many different purposes. It can assist the extraction of concepts from unstructured textual documents (Embley, Campbell, Smith, & Liddle, 1998) by serving as a source of knowledge about the particular topic. In addition, it can also assist in managing documents descriptions in large digital libraries (Weinstein & Alloway, 1997).
The understanding about digital library is quite different according to its specific users. A digital library is a Web-based electronic storage and access environment for information stored in the digital format either locally in a library, in a group of networked libraries, or at a remote location (Cleveland, 1998). It also means an integrated set of services for capturing, cataloging, storing, searching, protecting, and retrieving information. It comprises digital collections, services, and infrastructure to support lifelong learning, research, scholarly communication, and preservation.
Key Terms in this Chapter
E-Learning: Any technologically mediated learning using computers, whether from a distance or in face-to-face classroom setting (computer-assisted learning). It can cover a wide set of applications and processes such as Web-based learning, computer-based learning, virtual classrooms, and digital collaboration.
Semantics: Refers to the aspects of meaning that are expressed in a language, code, or other form of representation. Semantics is contrasted with two other aspects of meaningful expression, namely, syntax, which is the construction of complex signs from simpler signs, and pragmatics, which is the practical use of signs by agents or communities of interpretation in particular circumstances and context.
Ontological Search: A new type of search engine that understands semantics and the meaning of whole phrases, rather than just looking for individual words or groups of words
Ontology: A data model that represents a domain and is used to reason about the objects in that domain and the relations between them.
Lifelong Learning: A continuum of the learning process that takes place at all levels, that is, formal, nonformal, and informal, utilizing various modalities such as distance learning and conventional learning. Also known as continuing education
Search Engine: Software that enables users to search the Internet using keywords.
Digital Library: A collection of texts, images, and so forth encoded so as to be stored, retrieved, and read by the computer. It comprises digital collections, services, and infrastructure to support lifelong learning, research, scholarly communication, and preservation.
Semantic Web: An extension of the current Web that will allow a user to find, share, and combine information more easily. It relies on machine-readable information and metadata expressed in resource description framework (RDF). RDF is a family of World Wide Web Consortium (W3C) specifications originally designed as a metadata model using XML but which has come to be used as a general method of modeling knowledge through a variety of syntax formats (XML and non-XML).
Domain Ontology: Domain ontology, or domain-specific ontology, models a specific domain, or part of the world. It represents the particular meanings of terms as they apply to that domain.