Semantic information portals

Lecture Notes in Computer Science

Saarela

2006

Abstract. View-based search provides a promising paradigm for formulating complex semantic queries and representing results on the Semantic Web. A challenge for the application of the paradigm is the complexity of providing view-based search services through application programming interfaces (API) and web services. This paper presents a solution on how semantic view-based search can be provided efficiently through an API or as web service to external applications. The approach has been implemented as the open source tool Ontogator, that has been applied successfully in several practical semantic portals on the web. Keywords: semantic view-based search, view projection, Semantic Web middleware Interfacing Search ServicesThe Semantic Web enables querying data based on various combinations of semantic relationships. Because of the RDF data model, these queries are usually drafted as possibly complex sets of semantic relation patterns. An example would be "Find all toys manufactured in Europe in the 19th century, used by someone born in the 20th century". Here "toys", "Europe", "the 18th century", "someone" and "the 19th century" are ontological class restrictions on nodes and "manufactured in", "used by" and "time of birth" are the required connecting arcs in the pattern. While such queries are easy to formalize and query as graph patterns, they remain problematic because they are not easy for users to formulate. Therefore, much of the research in complex semantic queries has been on user interfaces [1,2] for creating complex query patterns as intuitively as possible.View-based search [3,4] is a search interface paradigm based on a longrunning library tradition of faceted classification [5]. Usability studies done on view-based search systems, such as Flamenco [6,4] and Relation Browser++ [7] have proved the paradigm both powerful and intuitive for end-users, particularly in drafting complex queries. Thus, view-based search presents a promising

Section: Related Implementationsmentioning

confidence: 99%

Ontogator — A Semantic View-Based Search Engine Service for Web Applications

Mäkelä

Lecture Notes in Computer Science

Saarela

2006

“…Portal types include service portals collecting a large set of services together into a localized miniature version of the web (e.g., Yahoo! and other "start pages"), community portals [2] acting as a virtual meeting place of a community, and information portals [3] acting as hubs of data. This paper discusses problems concerning information portals when publishing health information on the web for the citizens.…”

Section: Introductionmentioning

confidence: 99%

“…The content for the prototype (ca. 6000 web documents) was created by the National Public Health Institute (KTL) 3 , the UKK Institute 4 , the Finnish Institute of Occupational Health 5 , the national Suomi.fi citizen's portal 6 , and the Ministry of Justice 7 , and new organizations are joining in. In the following, problems of finding and producing health information on the web are first outlined.…”

Section: Introductionmentioning

confidence: 99%

HealthFinland —Finnish Health Information on the Semantic Web

Lecture Notes in Computer Science

Viljanen

Suominen

2007

Abstract. This paper shows how semantic web techniques can be applied to solving problems of distributed content creation, discovery, linking, aggregation, and reuse in health information portals, both from end-users' and content publishers' viewpoints. As a case study, the national semantic health portal HEALTH-FINLAND is presented. It provides citizens with intelligent searching and browsing services to reliable and up-to-date health information created by various health organizations in Finland. The system is based on a shared semantic metadata schema, ontologies, and ontology services. The content includes metadata about thousands of web documents such as web pages, articles, reports, campaign information, news, services, and other information related to health.

“…Portal types include service portals collecting a large set of services together (e.g., Yahoo! and other "start pages"), community portals [46] acting as virtual meeting places of communities, and information portals [36] acting as hubs of data. Much of the semantic web content will be published using semantic information portals [31,36].…”

mentioning

confidence: 99%

Semantic Portals for Cultural Heritage

2009

Handbook on Ontologies

Cultural content on the web is available in various forms (documents, images, audio tracks, videos, collection items, learning objects etc.), concern various topics (art, history, handicraft, etc.), is written in different languages, is targeted to both laymen and experts, and is provided by different independent memory organizations (museums, archives, libraries) and individuals. The difficulty of finding and relating information in this kind of heterogenous content provision and data format environment creates an obstacle for end-users of cultural contents, and a challenge to organizations and communities producing the contents.Portals try to ease these problems by collecting content of various publishers into a single site [43]. Portal types include service portals collecting a large set of services together (e.g., Yahoo! and other "start pages"), community portals [46] acting as virtual meeting places of communities, and information portals [36] acting as hubs of data. Much of the semantic web content will be published using semantic information portals [31,36]. Such portals are based on semantic web standards 1 and machine "understandable" content, i.e., metadata, ontologies, and rules, in order to improve structure, extensibility, customization, usability, and sustainability of traditional portal designs.Cultural heritage is a promising application domain for semantic portals [20,41,50]. They are useful from the end-users' view point in several ways:• Global view to heterogeneous, distributed contents. The contents (e.g., museum collections) of different content providers can be provided through one service as if it were a single, seamless homogenous repository [20]. Only a single user interface has to be learned.• Automatic content aggregation. Satisfying an end-user's information need often requires aggregation of content from several information providers [43,21] about an artist, relevant information may be provided by museum collections, libraries, archives, authority records, ontologies, and other sources.• Semantic search. In traditional portals search is usually based on free text search (e.g., Google), database queries, and/or a stable classification hierarchy (e.g., Yahoo! and dmoz.org). Semantic content makes it possible to provide the end-user with more "intelligent" facilities based on ontological concepts and structures, such as semantic search [7], semantic autocompletion [19], and (multi-)faceted semantic search [35,15,24,40,51] Semantic portals are very attractive from the content publishers viewpoint, too:• Distributed content creation. Portal content is usually created in a centralized fashion by using a content management system (CMS). This approach is costly and not feasible if content is created in a distributed fashion by independent publishers, e.g, by different of museums and other memory organizations. Semantic technologies can be used for harvesting and aggregating distributed heterogenous content (semi-)automatically into global content portals [20].• Automated link maintenance....