Search (10 results, page 1 of 1)

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Abstract

In 2004, the German Federal Ministry for Education and Research funded a major terminology mapping initiative at the GESIS Social Science Information Centre in Bonn (GESIS-IZ), which will find its conclusion this year. The task of this terminology mapping initiative was to organize, create and manage 'crossconcordances' between major controlled vocabularies (thesauri, classification systems, subject heading lists) centred around the social sciences but quickly extending to other subject areas. Cross-concordances are intellectually (manually) created crosswalks that determine equivalence, hierarchy, and association relations between terms from two controlled vocabularies. Most vocabularies have been related bilaterally, that is, there is a cross-concordance relating terms from vocabulary A to vocabulary B as well as a cross-concordance relating terms from vocabulary B to vocabulary A (bilateral relations are not necessarily symmetrical). Till August 2007, 24 controlled vocabularies from 11 disciplines will be connected with vocabulary sizes ranging from 2,000 - 17,000 terms per vocabulary. To date more than 260,000 relations are generated. A database including all vocabularies and cross-concordances was built and a 'heterogeneity service' developed, a web service, which makes the cross-concordances available for other applications. Many cross-concordances are already implemented and utilized for the German Social Science Information Portal Sowiport (www.sowiport.de), which searches bibliographical and other information resources (incl. 13 databases with 10 different vocabularies and ca. 2.5 million references).
In the final phase of the project, a major evaluation effort is under way to test and measure the effectiveness of the vocabulary mappings in an information system environment. Actual user queries are tested in a distributed search environment, where several bibliographic databases with different controlled vocabularies are searched at the same time. Three query variations are compared to each other: a free-text search without focusing on using the controlled vocabulary or terminology mapping; a controlled vocabulary search, where terms from one vocabulary (a 'home' vocabulary thought to be familiar to the user of a particular database) are used to search all databases; and finally, a search, where controlled vocabulary terms are translated into the terms of the respective controlled vocabulary of the database. For evaluation purposes, types of cross-concordances are distinguished between intradisciplinary vocabularies (vocabularies within the social sciences) and interdisciplinary vocabularies (social sciences to other disciplines as well as other combinations). Simultaneously, an extensive quantitative analysis is conducted aimed at finding patterns in terminology mappings that can explain trends in the effectiveness of terminology mappings, particularly looking at overlapping terms, types of determined relations (equivalence, hierarchy etc.), size of participating vocabularies, etc. This project is the largest terminology mapping effort in Germany. The number and variety of controlled vocabularies targeted provide an optimal basis for insights and further research opportunities. To our knowledge, terminology mapping efforts have rarely been evaluated with stringent qualitative and quantitative measures. This research should contribute in this area. For the NKOS workshop, we plan to present an overview of the project and participating vocabularies, an introduction to the heterogeneity service and its application as well as some of the results and findings of the evaluation, which will be concluded in August.

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Abstract

A variety of schemas and ontologies are currently used for the machine-readable description of bibliographic entities and citations. This diversity, and the reuse of the same ontology terms with different nuances, generates inconsistencies in data. Adoption of a single data model would facilitate data integration tasks regardless of the data supplier or context application. In this paper we present the OpenCitations Data Model (OCDM), a generic data model for describing bibliographic entities and citations, developed using Semantic Web technologies. We also evaluate the effective reusability of OCDM according to ontology evaluation practices, mention existing users of OCDM, and discuss the use and impact of OCDM in the wider open science community.

Type

a

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Abstract

In this paper we analyze a major part of the research output of the Networked Knowledge Organization Systems (NKOS) community in the period 2000 to 2015 from a network analytical perspective. We fo- cus on the paper output presented at the European NKOS workshops in the last 15 years. Our open dataset, the "NKOS bibliography", includes 14 workshop agendas (ECDL 2000-2010, TPDL 2011-2015) and 4 special issues on NKOS (2001, 2004, 2006 and 2015) which cover 171 papers with 218 distinct authors in total. A focus of the analysis is the visualization of co-authorship networks in this interdisciplinary eld. We used standard network analytic measures like degree and betweenness centrality to de- scribe the co-authorship distribution in our NKOS dataset. We can see in our dataset that 15% (with degree=0) of authors had no co-authorship with others and 53% of them had a maximum of 3 cooperations with other authors. 32% had at least 4 co-authors for all of their papers. The NKOS co-author network in the "NKOS bibliography" is a typical co- authorship network with one relatively large component, many smaller components and many isolated co-authorships or triples.

Type

a

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Abstract

Users of web search engines are known to mostly focus on the top ranked results of the search engine result page. While many studies support this well known information seeking pattern only few studies concentrate on the question what users are missing by neglecting lower ranked results. To learn more about the relevance distributions in the so-called long tail we conducted a relevance assessment study with the Million Short long-tail web search engine. While we see a clear difference in the content between the head and the tail of the search engine result list we see no statistical significant differences in the binary relevance judgments and weak significant differences when using graded relevance. The tail contains different but still valuable results. We argue that the long tail can be a rich source for the diversification of web search engine result lists but it needs more evaluation to clearly describe the differences.

Type

a

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Abstract

Purpose: To provide a critical review of Bergman's 2001 study on the Deep Web. In addition, we bring a new concept into the discussion, the Academic Invisible Web (AIW). We define the Academic Invisible Web as consisting of all databases and collections relevant to academia but not searchable by the general-purpose internet search engines. Indexing this part of the Invisible Web is central to scien-tific search engines. We provide an overview of approaches followed thus far. Design/methodology/approach: Discussion of measures and calculations, estima-tion based on informetric laws. Literature review on approaches for uncovering information from the Invisible Web. Findings: Bergman's size estimate of the Invisible Web is highly questionable. We demonstrate some major errors in the conceptual design of the Bergman paper. A new (raw) size estimate is given. Research limitations/implications: The precision of our estimate is limited due to a small sample size and lack of reliable data. Practical implications: We can show that no single library alone will be able to index the Academic Invisible Web. We suggest collaboration to accomplish this task. Originality/value: Provides library managers and those interested in developing academic search engines with data on the size and attributes of the Academic In-visible Web.

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Content

This study investigates the development of open access (OA) to journal articles from authors affiliated with German universities and non-university research institutions in the period 2010-2018. Beyond determining the overall share of openly available articles, a systematic classification of distinct categories of OA publishing allowed us to identify different patterns of adoption of OA. Taking into account the particularities of the German research landscape, variations in terms of productivity, OA uptake and approaches to OA are examined at the meso-level and possible explanations are discussed. The development of the OA uptake is analysed for the different research sectors in Germany (universities, non-university research institutes of the Helmholtz Association, Fraunhofer Society, Max Planck Society, Leibniz Association, and government research agencies). Combining several data sources (incl. Web of Science, Unpaywall, an authority file of standardised German affiliation information, the ISSN-Gold-OA 3.0 list, and OpenDOAR), the study confirms the growth of the OA share mirroring the international trend reported in related studies. We found that 45% of all considered articles during the observed period were openly available at the time of analysis. Our findings show that subject-specific repositories are the most prevalent type of OA. However, the percentages for publication in fully OA journals and OA via institutional repositories show similarly steep increases. Enabling data-driven decision-making regarding the implementation of OA in Germany at the institutional level, the results of this study furthermore can serve as a baseline to assess the impact recent transformative agreements with major publishers will likely have on scholarly communication.

Type

a

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Abstract

The German Federal Ministry for Education and Research funded a major terminology mapping initiative, which found its conclusion in 2007. The task of this terminology mapping initiative was to organize, create and manage 'cross-concordances' between controlled vocabularies (thesauri, classification systems, subject heading lists) centred around the social sciences but quickly extending to other subject areas. 64 crosswalks with more than 500,000 relations were established. In the final phase of the project, a major evaluation effort to test and measure the effectiveness of the vocabulary mappings in an information system environment was conducted. The paper reports on the cross-concordance work and evaluation results.

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Abstract

Im August 2009 wurde SKOS "Simple Knowledge Organization System" als neuer Standard für web-basierte kontrollierte Vokabulare durch das W3C veröffentlicht1. SKOS dient als Datenmodell, um kontrollierte Vokabulare über das Web anzubieten sowie technisch und semantisch interoperabel zu machen. Perspektivisch kann die heterogene Landschaft der Erschließungsvokabulare über SKOS vereinheitlicht und vor allem die Inhalte der klassischen Datenbanken (Bereich Fachinformation) für Anwendungen des Semantic Web, beispielsweise als Linked Open Data2 (LOD), zugänglich und stär-ker miteinander vernetzt werden. Vokabulare im SKOS-Format können dabei eine relevante Funktion einnehmen, indem sie als standardisiertes Brückenvokabular dienen und semantische Verlinkung zwischen erschlossenen, veröffentlichten Daten herstellen. Die folgende Fallstudie skizziert ein Szenario mit drei thematisch verwandten Thesauri, die ins SKOS-Format übertragen und inhaltlich über Crosskonkordanzen aus dem Projekt KoMoHe verbunden werden. Die Mapping Properties von SKOS bieten dazu standardisierte Relationen, die denen der Crosskonkordanzen entsprechen. Die beteiligten Thesauri der Fallstudie sind a) TheSoz (Thesaurus Sozialwissenschaften, GESIS), b) STW (Standard-Thesaurus Wirtschaft, ZBW) und c) IBLK-Thesaurus (SWP).