Semantic Web 2.0 (FinnONTO 2.0), 2008-2010

This paper presents the CultureSampo system for publishing heterogeneous linked data as a service. Discussed are the problems of converting legacy data into linked data, as well as the challenge of making the massively heterogeneous yet interlinked cultural heritage content interoperable on a semantic level. Novel user interface concepts for then utilizing the content are also presented. In the approach described, the data is published not only for human use, but also as intelligent services for other computer systems that can then provide interfaces of their own for the linked data. As a concrete use case of using CultureSampo as a service, the BookSampo system for publishing Finnish fiction literature on the semantic web is presented.

Ontologiat ovat keskeinen osa semanttista webiä: ne toimivat yhteisinä jaettuina käsitteistöinä, joiden avulla tietokoneet voivat käsitellä tietoa älykkäämmin. Jotta eri toimijat voivat hyödyntää yhteisiä käsitteistöjä sovelluksissaan, ontologiat on julkaistava heidän käyttöönsä. Yksinkertaisimmillaan ontologiat voidaan julkaista tiedostomuodossa. Tällöin jokainen toimija joutuu toteuttamaan itse toiminnallisuuksia ontologioiden hyödyntämiseen. Koska osa toiminnallisuuksista on yleisiä, useissa järjestelmissä toistuvia, niiden toteuttaminen valmiina palveluina on mielekästä. Palveluita voidaan tarjota ihmiskäyttäjille käyttöliittymäkomponentteina sekä ohjelmalliseen käyttöön rajapintoina, joita käyttämällä toiminnallisuudet voidaan integroida asiakasjärjestelmiin. Tässä artikkelissa kuvataan ontologioiden käyttäjäryhmien tarpeita sekä ontologiapalveluiden toteutuksia. Yleisten ontologioiden käyttämiseen liittyvien toiminnallisuuksien tarjoamiseksi esitetään ontologiapalvelu ONKI, joka on osa Suomalaiset semanttisen webin ontologiat -hankesarjassa (FinnONTO, 2003–2012) kehitettyä ontologiainfrastruktuuria. Artikkeli perustuu Jouni Tuomisen pro gradu -työhön, jolle Tietojenkäsittelytieteen Seura ry myönsi lukuvuoden 2009–2010 pro gradu -palkinnon. Tutkimustyöhön ovat osallistuneet myös Kim Viljanen ja Eero Hyvönen.

BookSampo is a semantic portal in use, covering metadata about practically all Finnish fiction literature of Finnish public libraries on a work level. The system introduces a variety of semantic web novelties deployed into practise: The underlying data model is based on the emerging functional, content-centered metadata indexing paradigm using RDF. Linked Data (LD) principles are used for mapping the metadata with tens of interlinked ontologies in the national FinnONTO ontology infrastructure. The contents are also linked with the large LD metadata repository of related cultural heritage content of CultureSampo. BookSampo is actually based on using CultureSampo as a semantic web service, demonstrating the idea of re-using semantic content from multiple perspectives without the need for modifications. Most of the content has been transformed automatically from existing databases, with the help of ontologies derived from thesauri in use in Finland, but in addtion tens of volunteered librarians have participated in a Web 2.0 fashion in annotating and correcting the metadata, especially regarding older litarature. For this purpose, semantic web editing tools and public ONKI ontology services were created and used. The paper focuses on lessons learned in the process of creating the semantic web basis of BookSampo.

This thesis explores the possibilities of using the view-based search paradigm to create intelligent user interfaces on the Semantic Web. After surveying several semantic search techniques, the view-based search paradigm is explained, and argued to fit in a valuable niche in the field. To test the argument, numerous portals with different user interfaces and data were built using the paradigm. Based on the results of these experiments, this thesis argues that the paradigm provides a strong, extendable and flexible base on which to built semantic user interfaces. Designing the actual systems to be as adaptable as possible is also discussed.

Publishing information about upcoming events such as concerts and discussion group meetings in a structured format allows the event information to be aggregated, filtered and delivered to potential participants. Making automatic personalized recommendations about events requires structured metadata such as machine-understandable locations and semantic descriptions about the topic and audience of the event. We present a survey of the state of current semantic representation formats for events, including iCalendar and its RDFa and microformat representations, and show that their support for expressing rich structured metadata is limited. We have also tested how well different tools support and understand the formats. Based on the surveys we have implemented a rich event information schema for a health-oriented activity portal and developed an aggregation and validation tool for gathering and processing event information.

Ontologiat luovat semanttisen webin perustan: ne toimivat yhteisinä jaettuina käsitteistöinä, joiden avulla tietokoneet voivat käsitellä tietoa älykkäämmin. Jotta eri toimijat voivat hyödyntää yhteisiä käsitteistöjä sovelluksissaan, ontologiat on julkaistava heidän käyttöönsä. Yksinkertaisimmillaan ontologiat voidaan julkaista datana, tiedostomuodossa. Tällöin jokainen toimija joutuu toteuttamaan itse toiminnallisuuksia ontologioiden hyödyntämiseen. Osa toiminnallisuuksista on yleisiä, useissa järjestelmissä toistuvia, kuten ontologian visualisointi, selaaminen ja käsitehaku. On kuitenkin kustannustehokkaampaa toteuttaa yleisiä ontologiatoiminnallisuuksia valmiina palveluina. Palveluita voidaan tarjota ihmiskäyttäjille käyttöliittymäkomponentteina sekä ohjelmalliseen käyttöön rajapintoina, joita käyttämällä toiminnallisuudet voidaan integroida asiakasjärjestelmiin. Lisäksi käytettäessä ontologioita palveluina toimijoiden käytössä on aina ontologioiden ajantasaiset versiot. Tässä tutkielmassa kuvataan ontologioiden käyttäjäryhmien -- ontologioiden kehittäjien, tiedon annotoijien, tiedon hakijoiden ja semanttisen webin sovellusten kehittäjien -- tarpeita sekä esitellään ontologioiden hyödyntämiseen kehitettyjä sovelluksia. Yleisten ontologioiden käyttämiseen liittyvien toiminnallisuuksien tarjoamiseksi esitetään ontologiapalvelu ONKI, joka julkistettiin virallisesti käyttöön syyskuussa 2008.

Providing citizens with reliable, up-to-date and individually relevant health information on the web is done by governmental, non-governmental, business and other organizations. Currently the information is published with little co-ordination and co-operation between the publishers. For publishers, this means duplicated work and costs due to publishing same information twice on many websites. Also maintaining links between websites requires work. From the citizens point of view, finding content is difficult due to e.g. differences in layman’s vocabularies compared to medical terminology and difficulties in aggregating information from several sites. To solve these problems, we propose as a solution a national scale semantic publishing system HealthFinland which consists of a 1) a centralized content infrastructure of health ontologies and services with tools, 2) a distributed semantic content creation channel based on several health organizations, and 3) an intelligent semantic portal aggregating and presenting the contents from intuitive and health promoting end-user perspectives for human users as well as for other web sites and portals.

Ihminen tarvitsee kuluttajana ja yrittäjänä usein toisten ihmisten ja organisaatioden tukea palveluiden muodossa. Aiemmin tuntemattomien palveluiden löytäminen voi kuitenkin olla vaikeaa Internetin tiedon määrän lisääntyessä, koska tiedonhakijalle mielekäs sisältö hau­tautuu helposti epäolennaisen tiedon joukkoon. Tämän ongelman helpottamiseksi semantti­sen webin tekniikat tarjoavat uusia mahdollisuuksia. Tässä diplomityössä tutkittiin millaisia palveluiden haun kannalta hyödyllisiä ratkaisuja on aiemmin toteutettu. Tämän jälkeen nämä ratkaisut peilattiin kahden Internetissä sijaitsevan palvelun, PKT­-säätiön ylläpitämä Yrityksen palveluhakemisto ja Suomen Asiakastiedon ylläpitämä Aarre­palvelu, parannusehdotuksiksi. Tutkittuja palveluita ehdotettiin tässä diplomityössä parannettavan useilla erilaisilla tavoil­la. Näistä osalla ei ollut suoraan mitään tekemistä semanttisen webin tekniikoiden kanssa ja osa taas liittyi semanttiseen webiin hyvin kiinteästi. Erityisesti maantieteellisen tiedon käsittelyssä havaittiin olevan runsaasti kehitettävää molempien tutkittujen palveluiden koh­dalla. Myös eroja parannusehdotusten välillä oli havaittavissa. Johtuen Aarre­-palvelun suu­remmasta tietokannasta ja suuremmasta käyttäjäjoukosta siinä sanojen välisen verkon hyödyntäminen näytti olevan merkityksellisempää kuin Yrityksen palveluhakemiston koh­dalla.

Historical texts are an important component of cultural heritage, and are being digitized and published on the web in various portals for the researhers and the public. However, searching and linking them with related contents is challenging due the non-structured text form, digitization errors, and the differences and variations between old and modern language, including historical names (e.g. places), used for querying. This paper addresses these issues by presenting an approach and a system for publishing old texts on the semantic web. As a case study, an existing historical newspaper archive on the web is considered. In our model, semantic metadata is added to the text using automated concept extraction methods. Search is implemented with semantic techniques, by creating a multi-faceted search interface for the text materials. Problems due to OCR errors and spelling variants are addressed with a fuzzy string matching algorithm trying to guess corresponding words in a lexicon, and giving suggestions for corrected words forms. References between texts in the library as well as links between the library and external knowledge sources are formed by using shared ontologies for semantic annotations.

Authors and documents with identical titles are common in the digital library environment. In order to manage identities correctly, authority control is used by library and information scientists for disam- biguating and cross-referencing entity names. We argue that the benefits of traditional authority control can be enhanced by using techniques and technologies of the Semantic Web, leading to simpler management of multiple languages, better linkability of resources, simpler reuse of au- thority registries in applications, and less work in indexing. To demon- strate our propositions, we have created a prototype of an ontology server and service called ONKI People that is used in two ways: First, it is a centralized authority service providing human end-users with efficient and easy to use authority finding and disambiguation services based on faceted semantic search and visualizations. The services are available on- line also as AJAX and Web Services API for machines to use. Second, the underlying RDF triple store can be used as a content resource in ap- plications such as semantic cultural heritage portals. The paper discusses and demonstrates both use cases in a real life setting.

The Semantic Web extends traditional web documents, i.e. the Web of Pages, with conceptual structures based on ontologies and metadata, i.e. the Web of Data. This paper presents a hybrid document search approach combining the benefits of the traditional text search of literal documents and the semantic search based on their underlying conceptual structures. The approach is based on document expansion, where documents are automatically annotated with not only the concepts explicitly present in a given document, but also with the ontologically related concepts using smaller weights. Our test results using the CLEF Test Suite suggest that document expansion alone achieves better recall than text search at the expense of precision. As a solution, a method of combining document expansion with text search is presented in which better recall was obtained without sacrificing precision. This approach seems promising when integrating unstructured, textual content with the Semantic Web of Data.

This paper discusses problems of creating and using ontology library services in production use. One approach to a solution is presented with an online implementation--the Finnish Ontology Library Service ONKI--that is in pilot use on a national level in Finland. ONKI contributes to previous research on ontology libraries in many ways: First, mashup and web service support with various tools is provided for cost-efficient utilization of ontologies in indexing and search applications. Second, services covering the different phases of the ontology life cycle are provided. Third, the services are provided and used in real world applications on a national scale. Fourth, the ontology framework is being developed by a collaborative effort by organizations representing different application domains, such as health, culture, and business.

Vocabularies are the building blocks of the Semantic Web providing shared terminological resources for content indexing, information retrieval, data exchange, and content integration. Most semantic web applications in practical use are based on lightweight ontologies and, more recently, on the Simple Knowledge Organization System (SKOS) data model being standardized by W3C. Easy and cost-efficient publication, integration, and utilization methods of vocabulary services are therefore highly important for the proliferation of the Semantic Web. This paper presents the ONKI SKOS Server for these tasks. Using ONKI SKOS, a SKOS vocabulary or a lightweight ontology can be published on the web as ready-to-use services in a matter of minutes. The services include not only a browser for human usage, but also Web Service and AJAX interfaces for concept finding, selecting and transporting resources from the ONKI SKOS Server to connected systems. Code generation services for AJAX and Web Service APIs are provided automatically, too. ONKI SKOS services are also used for semantic query expansion in information retrieval tasks. The idea of publishing ontologies as services is analogous to Google Maps. In our case, however, vocabulary services are provided and mashed-up in applications. ONKI SKOS was published in the beginning of 2008 and is to our knowledge the first generic SKOS server of its kind. The system has been used to publish and utilize some 60 vocabularies and ontologies in the National Finnish Ontology Service ONKI www.yso.fi.

Semantic web techniques can be used to relate two things together. However, usually this relation is not accompanied with a measure that would tell how interesting the relation is. Data mining tradition provides interestingness measures; it is natural to try and fit semantic web and data mining traditions together. In this paper we use support and confidence values provided by association rule mining as interestingness measures for relations. The presented method is tailored to location ontologies in order to find out what interesting mutual relations two places have based on annotations in the cultural heritage domain. The method also uses ontology-based reasoning to group places together. We present tests of running the method against a set of over 60,000 annotations in order to find out cultural heritage connections between places.

In this paper we present an ontology-based query expansion widget which utilizes the ontologies published in the ONKI Ontology Service. The widget can be integrated into a web page, e.g. a search system of a museum catalogue, enhancing the page by providing a query expansion functionality. We have tested the system with general, domain-specific and spatio-temporal ontologies.

Ontologies aim to capture knowledge about things and their relationships. Publishing ontologies on the Semantic Web enables people and organizations to use shared ontologies in annotating e.g. photographs, videos, music, and other types of cultural objects. Search engines also use relationships provided by ontologies in semantic search, e.g. for query expansion or for view-based search. However, building ontologies is a time-consuming process, and it should be helped by automatic finding of interesting, possible relationships. Finding the correct concept for annotation purposes is helped by subsumption and partonomy hierarchies and associative relationships. In this paper we show how an analysis of co-occurrences of concepts in annotations can be used to provide interesting relationships for enriching ontological structures. We use association rule mining techniques and test the idea using a set of annotations of cultural objects in CULTURESAMPO portal and the Finnish General Upper Ontology YSO. The results are visualized in the ONKI SKOS browser to give an additional layer on top of the original relationships of the YSO ontology. An analysis shows that best ranked relationships should also be included in the ontology as subclassof or associative relationships.

Artikkelissa luodaan katsaus kansallisessa Suomalaiset semanttisen webin ontologiat hankkeessa FinnONTO 2003-2007 ja FinnONTO 2.0 2008-2010 kehitettyihin paikkaontologioihin SUO (Suomalainen paikkaontologia) ja SAPO (Suomen ajallinen paikkaontologia), näiden julkaisemiseen AJAX-palveluina Kansallisessa ontologiapalvelussa ONKI, sekä paikkaontologioiden avulla Kulttuurisampo-portaaliin kehitettyihin palveluhin.

Kulttuurisampo kokoaa suomalaisen kulttuurin palapeliä aivan uudella tavalla, kirjoittavat Eero Hyvönen ja Suvi Kettula

This paper presents the national level cross-domain ontology and ontology service infrastructure ONKI used in Finland. The novelty of ONKI is based on two ideas. First, the core ontologies are developed collaboratively by experts transforming thesauri into mutually aligned lightweight ontologies, based on a large top ontology that is extended by various domain specific ontologies. Second, the National Ontology Service ONKI has been implemented for publishing ontologies cost-efficiently as ready to use services. ONKI provides legacy and other applications with ready to use functionalities for using ontologies on the HTML level by Ajax and semantic widgets. ONKI has been used in various applications for creating mash-up applications in a way analogous to using Google Maps, but in our case external applications are mashed-up with ontology support for indexing and information retrieval.

Thesauri and other controlled vocabularies act as building blocks of the Semantic Web by providing shared terminology for facilitating information retrieval, data exchange and integration. Representation and publishing methods are needed for utilizing thesauri efficiently, e.g., in content indexing and searching. W3C has provided the Simple Knowledge Organization System (SKOS) data model for expressing concept schemes, such as thesauri. A standard representation format for thesauri eliminates the need for implementing thesaurus specific rules or applications for processing them. However, there do not exist general tools which provide out of the box support for publishing and utilizing SKOS vocabularies in applications, without needing to implement application specific user interfaces for end users. For solving this problem the ONKI-SKOS server is presented.

Finding people is essential in finding information. Librarians and information scientists have studied authority control - psychologists and sociologists social networks. In aforementioned, authors link to documents (and co-authors) creating access points to information. In latter, social paths serve as channels for rumours as well as expertise. Key problems include identification and disambiguation of individuals followed by difficulties of tracking the social connections. With semantic web, these aspects can be approached simultaneously. In this paper, we define a simple ontology for describing people and organizations. The model is based on FOAF and other existing vocabularies. We also demonstrate search and visualization tools for finding people.

The Semantic Web is based on using ontologies for enabling semantically disambiguated data exchange between distributed systems on the web. This requires efficient means for publishing ontologies on the web to ensure the availability, sharing and acceptance of the ontologies. Support services are needed for utilizing ontologies easily and cost-effectively in applications and legacy systems lacking ontology support. To address these vital needs, this paper presents the ONKI ontology service which provides ready-to-use mash-up functionalities, such as semantic disambiguation, concept finding and concept fetching as ready-to-use web widgets for adding ontology support to e.g. HTML forms using JavaScript. Two implementations of the ONKI Server are presented: ONKI-SKOS for ontologies presented in the Simple Knowledge Organization System (SKOS) language and ONKI-Geo for geographical ontologies with a map interface. The presented ONKI systems are operational on the web, used in the National Finnish Ontology Service. They have been successfully used in several pilot applications.

This article presents the vision and results of creating a national level cross-domain ontology service infrastructure in Finland in the FinnONTO project. The novelty of the infrastructure is based on two ideas. First, a system of open source core ontologies is being developed by transforming thesauri into mutually aligned lightweight ontologies, including a top ontology of 20,000 concepts that is extended by various domain specific ontologies. Second, the ONKI Ontology Server framework for publishing ontologies as ready to use services has been designed and implemented. ONKI provides legacy and other applications with ready to use functionalities for using ontologies on the user interface level as semantic widgets. The idea is to use ONKI for creating mash-up applications in a way analogous to using Google or Yahoo Maps, but in our case external applications are mashed-up with ontology support. The ontology framework presented is operational on the web and is being used in creating the application demonstrations.

This paper presents the semantic portal CULTURESAMPO---Finnish Culture on the Semantic Web . The portal provides memory organizations and other cultural content publishers with a national, shared semantic publication channel for heteroge- nous cultural contents. The content comes from over ten organizations and is annotated using various ontologies of the FinnONTO infrastructure. For the end-user, intel- ligent semantic search, recommendation, and visualization services for accessing and learning about cultural heritage are provided.

Content annotations in semantic cultural heritage portals commonly make spatiotemporal references to historical regions and places using names whose meanings are different in different times. For example, historical administrational regions such as countries, municipalities, and cities have been renamed, merged together, split into parts, and annexed or moved to and from other regions. Even if the names of the regions remain the same (e.g., “Germany”), the underlying regions and their relationships to other regions may change (e.g., the regional coverage of “Germany” at different times). As a result, representing and finding the right ontological meanings for historical geographical names on the semantic web creates severe problems both when annotating contents and during information retrieval. This paper presents a model for representing the meaning of changing geospatial resources. Our aim is to enable precise annotation with temporal geospatial resources and to enable semantic search and browsing using related names from other historical time periods. A simple model and metadata schema is presented for representing and maintaining geospatial changes from which an explicit time series of temporal part-of ontologies can be created automatically. The model has been applied successfully to representing the complete change history of municipalities in Finland during 1865–2007, and the resulting ontology time series is used in the semantic cultural heritage portal CULTURESAMPO to support faceted semantic search of contents and to visualizing historical regions on overlaying maps originating from different historical eras.

Many tasks on the semantic web require the user to choose concepts from a limited vocabulary e.g. for describing an indexed resource or for use in semantic search. Semantic autocompletion interfaces offer an efficient way for concept selection. However, these interfaces usually do not expose the semantic context of the matched concepts, thereby making it hard to know if a matched concept is the right one, as well as hiding possibly more appropriate choices. Ontology browsers, on the other hand, show context but do not allow quick discovery or embedding into other applications. To lessen these problems, we present an interface combining semantic autocompletion with in-place ontological context navigation. Because required context differs between ontologies, the implementation was designed to make it easy to add different contexts and visualizations. To test the applicability of our idea and implementation the, system was tested on three ontologies with different requirements and structure.

Geographic place names are semantically often highly ambiguous. For example, there are 491 places in Finland sharing the same name ”Isosaari” (great island) that are instances of several geographical classes, such as Island, Forest, Peninsula, Inhabited area, etc. Referencing unambiguously to a particular ”Isosaari”, either when annotating content or during information retrieval, can be quite problematic and requires usage of advanced search methods and maps for semantic disambiguation. Historical places introduce even more challenges, since historical metadata commonly make spatiotemporal references to historical regions and places using names whose meanings are non-existing or different in different times. This paper presents how these problems have been addressed in a large Finnish place ontology SUO and a historical geo-ontology SAPO. A location ontology server ONKI-Geo has been created for publishing the ontologies and utilizing them as mashup services. To demonstrate the usability of our ontologies, two case applications in the cultural heritage domain are presented.

Tämä diplomityö käsittelee menetelmiä, joilla paikkatietoaineistoja muunnetaan ontologiseen muotoon sekä esittelee palvelun, ONKI-Paikan, jolla ontologisessa muodossa olevaa paikkatietoa voidaan tuottaa, ylläpitää ja hakea. Palvelu perustuu paikkatiedon mallintamiseen Suomalaisen paikkaontologian SUO:n mukaisesti. Työ koostuu neljästä vaiheesta. Ensimmäisessä vaiheessa selvitetään menetelmä, jolla SUO-ontologia populoidaan paikkainstansseilla. Erityistä huomiota kiinnitetään paikkojen uniikkien tunnisteiden, URI:en luomiseen. Toisessa vaiheessa selvitetään, miten ontologian populointivaiheessa tuotetut paikkojen RDF-kuvaukset on tallennettava. Kolmannessa vaiheessa ratkotaan ontologisessa muodossa olevan paikkatietoaineiston suuren määrän tuomia ongelmia muun muassa kehittämällä paikkatiedon RDF-varastolle indeksointitietokanta nopeita hakuja varten. Neljännessä vaiheessa kehitetään rajapinta hakujen suorittamista varten sekä hakurajapintaa hyödyntävä graafinen, selaimessa toimiva käyttöliittymä. Työ on tehty osana FinnONTO-projektia, jossa kehitettiin suomalaisiin olosuhteisiin räätälöityjä semanttisen webin ontologioita sekä näitä hyödyntäviä palveluita.

Semanttisen webin ideana on kuvailla tietoa siten, että koneet pystyvät ymmärtämään sitä, ja käyttämään älykkäitä tekniikoita tiedon hyödyntämiseksi. Tiedon kuvailemise käytetään ontologioita jotka muodostavat laajoja käsiteverkkoja. Kuvailua varten ontologiasta on läydettävä tarkimmin kohdetta kuvaavat käsitteet. Tässä työssä tutkittiin minkälaisia menetelmiä käsitteenvalintaan on kehitetty ja millä tavoin käsitteenvalintaa voidaan tukea visuaalisin keinoin. Lisäksi perehdyttiin joihinkin semanttisen webin sovelluksiin niiden käsitteenvalinnan osalta. Käsitevalitsimissa havaittiin puutteita liittyen käsitteiden merkityksen disambiguointiin ja siihen, kuinka helppoa niiden avulla on valita paras käsite kuvaamaan tietoa. Ongelmia oli myös tavoissa esittää useiden ontologioiden yhdistelmiä. Näiden havaintojen pohjalta suunniteltiin ja toteutettiin yleinen ja monentyyppisen aineiston käsittelyyn soveltuva käsitevalitsin IRMA

In this paper we examine 1) the scope of geo-ontologies used especially for the purposes of information retrieval on the Web, 2) the core geographical concepts and their mutual relations, and 3) the properties the concepts have. Furthermore, we present the Finnish geo-ontology (Suomalainen paikkaontologia, SUO) and discuss the theories and principles that have governed the development process, as well as the limitations and requirements the use of geographical dictionaries as an instance data source have imposed to the content and the structure of SUO.

Cultural heritage is by nature strongly interlinked, e.g. thematically and historically, but at the same time distributed in heterogeneous collections of different memory organizations at different locations. In order to provide the end-users with aggregated homogeneous views to distributed heterogeneous contents, semantic portals have been created successfully based on metadata and shared (or aligned) ontologies. This paper discusses two problems encountered in such a distributed semantic content creation environment. First, during the content creation work, how could a publisher start using shared ontologies in legacy cataloguing and annotation systems that do not support ontologies. Second, during content publication, how could a publisher re-use the aggregated content in its own legacy publication system, e.g., on the ordinary web pages of a museum or in a collection browser. As a solution, we present the ONKI Ontology Server for adding shared ontological annotation functionalities to legacy cataloguing systems in a practical, cost-efficient and lightweight way. For distributed publishing of the aggregated semantic portal services, we introduce the lightweight mash-up web widget components called floatlets . A major idea behind both the ONKI functionalities and floatlets is that they can be easily integrated with legacy systems on the user interface level, in the same spirit as e.g. Google Maps.

Informaation lisääntyessä yhteiskunnassa vaaditaan sen tehokasta käsittelyä yhä enemmän ammattilaisten lisäksi myös tavallisilta käyttäjiltä. Tällöin luonnollinen pyrkimys on yksinkertaistaa ja automatisoida tiedonhakuprosessia mahdollisimman paljon, johon semanttisen webin tekniikat tarjoavat uusia mahdollisuuksia. Tässä diplomityössä tutkittiin mahdollisuuksia dokumentin laajentamisen ja ontologisten käsitteiden hyödyntämisen kautta parantaa tiedonhakuprosessia tekstipohjaiseen aineistoon, kuten sanomalehtiarkistoon. Tätä tarkoitusta varten luotiin automaattinen annotointi ja hakusovellus Airo, joka suorittaa jonkin annetun ontologian pohjalta dokumentin laajennuksen. Tämä tapahtuu ontologisella käsiteklusteroinnilla, jossa jonkin käsitteen esiintyminen tekstissä nostaa myös ontologian hierarkiassa läheisten käsitteiden painoa kyseistä dokumenttia indeksoitaessa ja haettaessa. Järjestelmän testit osoittivat, että käsitehaku yhdistettynä sanahakuun laskee haun tarkkuutta, mutta nostaa saantia. Sen sijaan hybridimenetelmä dokumentin- ja kyselyn laajennuksesta, jossa perinteisen sanahaun tuottamien dokumenttien käsitteillä suoritetaan laajentava haku, nosti saantia tarkkuuden kärsimättä. Luotu järjestelmä on ontologiariippumaton ja jokaisen ontologian tuottamat käsitteistykset talletetaan omaan indeksiinsä, jolloin niitä voidaan hakea erikseen.

Tiedonhakuun webissä on kehitetty sanahaun lisäksi rikkaampia tiedonhaku- ja selausmenetelmiä, jotka mahdollistavat tutkivan tiedonhaun. Niistä on hyötyä silloin, kun käyttäjä ei etukäteen tiedä täsmälleen, mitä hän on etsimässä. Yksi tällainen hakukäyttöliittymätyyppi on moninäkymähaku, jossa haun kohteena oleva tietosisältö luokitellaan moniulotteiseksi avaruudeksi fasettiluokituksen periaattein. Käyttöliittymä mahdollistaa aineiston haun ja selaamisen minkä tahansa ulottuvuuden tai niiden yhdistelmän suhteen. Moninäkymähaun kehitys lähti liikkeelle käyttöliittymätutkimuksen piiristä. Moninäkymähakuun perustuvia käyttöliittymiä käytettiin myöhemmin semanttisen webin sovelluksissa ja portaaleissa, joissa kuitenkaan ei samassa määrin huomioitu käyttäjiä suunnitteluprosessin aikana. Tutkielmassa käyttäjäkeskeisiä suunnittelu- ja tiedonjäsennysmenetelmiä sovellettiin terveysaiheista materiaalia sisältävän tervesuomi.fi-portaalin suunnitteluun sekä toteutettiin moninäkymähakua käyttävä portaalin prototyyppi semanttisen webin teknologioiden avulla. Portaalin informaatioarkkitehtuuri suunniteltiin korttienjärjestämismenetelmän avulla ja sen käyttöliittymä rakennettiin käyttäjäkeskeisellä suunnittelu- ja arviointiprosessilla. Tulosten arviointi osoittaa, että käyttäjäkeskeisistä menetelmistä oli merkittävää hyötyä portaalin suunnittelussa. Valmiin prototyypin käytettävyyden arviointi osoitti, että portaalin käytettävyys on käyttäjäkeskeisten suunnittelu- ja arviointimenetelmien ansiosta saatu hyvälle tasolle. Arviointi myös paljasti portaalin aineistoissa, käyttöliittymässä ja tiedon jäsennystavassa ongelmia, joihin terveysportaalin jatkokehityksessä voidaan puuttua.

Creation of rich, ontology-based metadata is one of the major challenges in developing the Semantic Web. Emerging applications utilizing semantic web techniques, such as semantic portals, cannot be realized if there are no proper tools to provide metadata for them. This paper discusses how to make provision of metadata easier and cost-effective by an annotation framework comprising of annotation editor combined with shared ontology services. We have developed an annotation system supporting distributed collaboration in creating annotations, and hiding the complexity of the annotation schema and the domain ontologies from the annotators. Our system adapts flexibly to different metadata schemas, which makes it suitable for different applications. Support for using ontologies is based on ontology services, such as concept searching and browsing, concept URI fetching, semantic autocompletion and linguistic concept extraction. The system is being tested in various practical semantic portal projects.