12 research outputs found

    Categorized Graphical Overviews for Web Search Results: An Exploratory Study using U.S. Government Agencies as a Meaningful and Stable Structure

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    Search engines are very effective at generating long lists of results that are highly relevant to user-provided query terms. But the lack of effective overviews presents challenges to users who seek to understand these results, especially for a complex task such as learning about a topic area, which requires gaining overviews of and exploring large sets of search results, identifying unusual documents, and understanding their context. Categorizing the results into comprehensible visual displays using meaningful and stable classifications can support user exploration and understanding of large sets of search results. This extended abstract presents a set of principles that we are developing for search result visualization. It also describes an exploratory study that investigated categorized overviews of search results for complex search tasks within the domain of U. S. government web sites, using a hierarchy based on the federal government organization

    KOCIS-KD : コリアン・ディアスポラ情報集積のための1モデル

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    View-based user interfaces for the Semantic Web

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    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, extensible and flexible base on which to built semantic user interfaces. Designing the actual systems to be as adaptable as possible is also discussed

    Methods for Building Semantic Portals

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    Semantic portals are information systems which collect information from several sources and combine them using semantic web technologies into a user interface that solves information needs of users. Creating such portals requires methods and tools from multiple disciplines, including knowledge representation, information retrieval, information extraction, and user interface design. This thesis explores methods for building and improving semantic portals and other semantic web applications with contributions in three areas. The studies included in the thesis draw from the design science methodology in information systems research. First, a method for creating of faceted search user interfaces for semantic portals utilizing controlled vocabularies with a complex hierarchical structure is presented. The results show that the method allows the creation of user-centric search facets that hide the complex hierarchies from the user, resulting in a user-friendly faceted search interface. Second, the creation of structured metadata from text documents is enhanced by adapting a state of the art automatic subject indexing system to Finnish language texts. The results show that using a suitable combination of existing tools, automatic subject indexing quality comparable to that of human indexers can be attained in a highly inflected language such as Finnish. Finally, the quality of controlled vocabularies such as thesauri and lightweight ontologies is examined by developing a set of quality criteria for vocabularies expressed using the SKOS standard, and methods for correcting structural problems in SKOS vocabularies are presented. The results show that most published SKOS vocabularies suffer from quality issues and violate the SKOS integrity conditions. However, the great majority of such problems were corrected by the methods presented in this dissertation. The methods have been implemented in several real world applications, including the HealthFinland health information portal, the ARPA information extraction toolkit, and the ONKI ontology library system.Semanttiset portaalit ovat tietojärjestelmiä, jotka keräävät tietoa useista lähteistä ja yhdistävät ne semanttisen webin teknologioiden avulla käyttäjien tiedontarpeita tukevaksi käyttöliittymäksi. Tällaisten portaalien rakentaminen vaatii menetelmiä ja työkaluja useilta tieteenaloilta, mukaan lukien tietämyksen esittäminen, tiedonhaku, tiedon eristäminen ja käyttöliittymäsuunnittelu. Tässä väitöskirjassa tarkastellaan menetelmiä semanttisten portaalien ja muiden semanttisen webin sovellusten rakentamiseksi. Väitöskirjan tulokset jakaantuvat kolmeen osa-alueeseen. Tutkimuksessa käytetyt menetelmät perustuvat informaatiojärjestelmien tutkimuksessa käytettyihin suunnittelutieteen menetelmiin. Ensiksi väitöskirjassa esitetään menetelmä semanttisten portaalien fasettipohjaisten käyttöliittymien luomiseksi monimutkaisten kontrolloitujen sanastojen pohjalta. Tulokset osoittavat, että menetelmä mahdollistaa sellaisten käyttäjäkeskeisten hakunäkymien luomisen, jotka piilottavat monimutkaiset hierarkiat käyttäjältä ja auttavat siten luomaan käyttäjäystävällisen fasettipohjaisen hakukäyttöliittymän. Toiseksi rakenteisen metatiedon tuottamista tekstidokumenteista parannetaan sovittamalla nykyaikainen automaattisen sisällönkuvailun järjestelmä suomenkieliselle tekstiaineistolle. Tulokset osoittavat, että käyttämällä sopivaa yhdistelmää olemassaolevista työkaluista saavutetaan ihmistyönä tehtyyn sisällönkuvailuun verrattavissa oleva automaattisen sisällönkuvailun laatu myös agglutinatiivisella kielellä kuten suomen kielellä esitetyille aineistoille. Kolmanneksi tarkastellaan kontrolloitujen sanastojen kuten asiasanastojen ja kevytontologioiden laatua kehittämällä laatukriteeristö SKOS-standardin avulla esitetyille sanastoille sekä esittämällä menetelmiä SKOS-sanastojen rakenteisten ongelmien korjaamiseksi. Tulokset osoittavat, että useimmat julkaistut SKOS-sanastot kärsivät laatuongelmista eivätkä noudata SKOS-standardin eheyssääntöjä. Suuri osa näistä ongelmista pystyttiin korjaamaan tässä väitöskirjassa esitetyin menetelmin. Menetelmät on toteutettu useissa käytössä olevissa järjestelmissä, kuten TerveSuomi-terveystietoportaalissa, ARPA-tiedoneristämistyökalussa ja ONKI-ontologiakirjastossa

    Crisp, fuzzy, and probabilistic faceted semantic search

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    This dissertation presents contributions to the development of the faceted semantic search (FSS) paradigm. First, two fundamental solutions to FSS, which have been widely used since their development are presented. The first is the projection of search facets from annotation ontologies using logical rules. The second is the logic rule-based generation of recommendation links for search items based on the semantic relations of these items. After presenting these solutions, the rest of the dissertation focuses on solving the following deficiencies of FSS: the lack of capabilities to model uncertainty, the inability to rank search results according to relevance, and the usability problems resulting from naively using annotation ontology concepts as search categories. Two sets of solutions to these problems are presented. First, a fuzzy faceted semantic search (FFSS) framework is developed, which extends the crisp set basis of FSS to fuzzy sets. This framework is based on two main ingredients: First, weighted annotations, which are used to determine the membership degrees of search items in annotation concepts. Second, fuzzy mappings of separate end-user categories onto the annotation concepts. In addition, also a probabilistic faceted semantic search (PFSS) framework was developed, which incorporates weighted annotations, modeling of uncertainty in Semantic Web taxonomies, sophisticated mappings of end-user facets onto annotation ontologies, and the combination of evidence from multiple ranking schemes. These ranking methods were empirically analyzed. According to the preliminary evaluation both ranking methods significantly improve quality of search results compared to crisp FSS. Both also outperformed a currently used heuristical ranking method. However, in the case of FFSS this difference did not reach the level of statistical significance

    Deriving and applying facet views of the Dewey Decimal Classification Scheme to enhance subject searching in library OPACs

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    Classification is a fundamental tool in the organisation of any library collection for effective information retrieval. Several classifications exist, yet the pioneering Dewey Decimal Classification (DDC) still constitutes the most widely used scheme and international de facto standard. Although once used for the dual purpose of physical organisation and subject retrieval in the printed library catalogue, library classification is now relegated to a singular role of shelf location. Numerous studies have highlighted the problem of subject access in library online public access catalogues (OPACs). The library OPAC has changed relatively little since its inception, designed to find what is already known, not discover and explore. This research aims to enhance OPAC subject searching by deriving facets of the DDC and populating these with a library collection for display at a View-based searching OPAC interface. A novel method is devised that enables the automatic deconstruction of complex DDC notations into their component facets. Identifying facets based upon embedded notational components reveals alternative, multidimensional subject arrangements of a library collection and resolves the problem of disciplinary scatter. The extent to which the derived facets enhance users' subject searching perceptions and activities at the OPAC interface is evaluated in a small-scale usability study. The results demonstrate the successful derivation of four fundamental facets (Reference Type, Person Type, Time and Geographic Place). Such facet derivation and deconstruction of Dewey notations is recognised as a complex process, owing to the lack of a uniform notation, notational re-use and the need for distinct facet indicators to delineate facet boundaries. The results of the preliminary usability study indicate that users are receptive to facet-based searching and that the View-based searching system performs equally as well as a current form fill-in interface and, in some cases, provides enhanced benefits. It is concluded that further exploration of facet-based searching is clearly warranted and suggestions for future research are made.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Supporting Exploratory Web Search With Meaningful and Stable Categorized Overviews

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    This dissertation investigates the use of categorized overviews of web search results, based on meaningful and stable categories, to support exploratory search. When searching in digital libraries and on the Web, users are challenged by the lack of effective overviews. Adding categorized overviews to search results can provide substantial benefits when searchers need to explore, understand, and assess their results. When information needs are evolving or imprecise, categorized overviews can stimulate relevant ideas, provoke illuminating questions, and guide searchers to useful information they might not otherwise find. When searchers need to gather information from multiple perspectives or sources, categorized overviews can make those aspects visible for interactive filtering and exploration. However, they add visual complexity to the interface and increase the number of tactical decisions to be made while examining search results. Two formative studies (N=18 and N=12) investigated how searchers use categorized overviews in the domain of U.S. government web search. A third study (N=24) evaluated categorized overviews of general web search results based on thematic, geographic, and government categories. Participants conducted four exploratory searches during a two hour session to generate ideas for newspaper articles about specified topics. Results confirmed positive findings from the formative studies, showing that subjects explored deeper while feeling more organized and satisfied, but did not find objective differences in the outcomes of the search task. Results indicated that searchers use categorized overviews based on thematic, geographic, and organizational categories to guide the next steps in their searches. This dissertation identifies lightweight search actions and tactics made possible by adding a categorized overview to a list of web search results. It describes a design space for categorized overviews of search results, and presents a novel application of the brushing and linking technique to enrich search result interfaces with lightweight interactions. It proposes a set of principles, refined by the studies, for the design of exploratory search interfaces, including "Organize overviews around meaningful categories," "Clarify and visualize category structure," and "Tightly couple category labels to search result list." These contributions will be useful to web search researchers and designers, information architects and web developers
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