Diese Datenbank enthält über 40.000 Dokumente zu Themen aus den Bereichen Formalerschließung – Inhaltserschließung – Information Retrieval.
© 2015 W. Gödert, TH Köln, Institut für Informationswissenschaft / Powered by litecat, BIS Oldenburg (Stand: 13. Juni 2017)
21Dadashkarimia, J. ; Shakery, A. ; Failia, H. ; Zamani, H.: ¬An expectation-maximization algorithm for query translation based on pseudo-relevant documents.
In: Information processing and management. 53(2017) no.2, S.371-387.
Abstract: Query translation in cross-language information retrieval (CLIR) can be done by employing dictionaries, aligned corpora, or machine translators. Scarcity of aligned corpora for various domains in many language pairs intensifies the importance of dictionary-based CLIR which motivates us to use only a bilingual dictionary and two independent collections in source and target languages for query translation. We exploit pseudo-relevant documents for a given query in the source language and pseudo-relevant documents for a translation of the query in the target language with a proposed expectation-maximization algorithm for improving query translation. The proposed method (called EM4QT) assumes that each target term either is translated from the source pseudo-relevant documents or has come from a noisy collection. Since EM4QT does not directly consider term coherency, which is defined as fluency of the target translation, we investigate a crucial question: can EM4QT be improved using either coherency-based methods or token-to-token translation ones? To address this question, we combine different translation models via simple linear interpolation and a proposed divergence minimization method. Evaluations over four CLEF collections in Persian, French, Spanish, and German indicate that EM4QT significantly outperforms competitive baselines in all the collections. Our experiments also reveal that since EM4QT indirectly considers term coherency, combining the method with coherency-based models cannot significantly improve the retrieval performance. On the other hand, investigating the query-by-query results supports the view that EM4QT usually gives a relatively high weight to one translation and its combination with the proposed token-to-token translation model, which is obtained by running EM4QT for each query term separately, soothes the effect and reaches better results for many queries. Comparing the method with a competitive word-embedding baseline reveals the superiority of the proposed model.
Inhalt: Vgl.: http://www.sciencedirect.com/science/article/pii/S0306457316306379 [http://dx.doi.org/10.1016/j.ipm.2016.11.007].
22Tappenbeck, I. ; Wittich, A. ; Gäde, M.: Fit für die Vermittlung von Informationskompetenz? : Anforderungen an die Qualifikation von Teaching Librarians in bibliothekarischen Studiengängen und Ausbildungseinrichtungen.
In: o-bib: Das offene Bibliotheksjournal. 4(2017) Nr.1, S.32-47.
Abstract: Der Beitrag stellt zunächst die Ergebnisse einer Auswertung von Stellenanzeigen aus der Mailingliste InetBib vor, die zeigt, dass die Nachfrage nach Absolventinnen und Absolventen bibliothekarischer Studiengänge mit einer Qualifikation für den Aufgabenbereich der Vermittlung von Informationskompetenz seit dem Jahr 2000 signifikant gestiegen ist. Ergänzend hierzu präsentieren die Autorinnen die Ergebnisse einer Befragung unter Vertreterinnen und Vertretern der bibliothekarischen Berufspraxis zu im Bereich der Vermittlung von Informationskompetenz geforderten Kompetenzen und deren Gewichtung innerhalb der verschiedenen Qualifikationsstufen.
Inhalt: https://www.o-bib.de/article/view/2017H1S32-47. DOI: http://dx.doi.org/10.5282/o-bib/2017H1S32-47.
Anmerkung: Beitrag innerhalb eines Themenschwerpunktes zur Informationskompetenz aus, der in Zusammenarbeit mit der Gemeinsamen Kommission Informationskompetenz des VDB und des dbv entstanden ist.
Themenfeld: Informationsdienstleistungen ; Ausbildung
23Zimmer, J.C. ; Henry, R.M.: ¬The role of social capital in selecting interpersonal information sources.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.5-21.
Abstract: Although the information-seeking literature has tended to focus upon the selection and use of inanimate objects as information sources, this research follows the more recent trend of investigating how individuals evaluate and use interpersonal information sources. By drawing from the structural, relational, and cognitive elements of social capital theory to inform antecedents to information quality and source accessibility, a research model is developed and tested. For interpersonal information sources, information quality is the key determinant of source use. Perceptions of information quality and accessibility of an interpersonal source are shown to be influenced by boundary spanning, transactive memory, and content type. Implications and prescriptions for future research are discussed.
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23577/full.
24Ren, P. ; Chen, Z. ; Ma, J. ; Zhang, Z. ; Si, L. ; Wang, S.: Detecting temporal patterns of user queries.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.113-128.
Abstract: Query classification is an important part of exploring the characteristics of web queries. Existing studies are mainly based on Broder's classification scheme and classify user queries into navigational, informational, and transactional categories according to users' information needs. In this article, we present a novel classification scheme from the perspective of queries' temporal patterns. Queries' temporal patterns are inherent time series patterns of the search volumes of queries that reflect the evolution of the popularity of a query over time. By analyzing the temporal patterns of queries, search engines can more deeply understand the users' search intents and thus improve performance. Furthermore, we extract three groups of features based on the queries' search volume time series and use a support vector machine (SVM) to automatically detect the temporal patterns of user queries. Extensive experiments on the Million Query Track data sets of the Text REtrieval Conference (TREC) demonstrate the effectiveness of our approach.
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23578/full.
25Rowley, J. ; Johnson, F. ; Sbaffi, L.: Gender as an influencer of online health information-seeking and evaluation behavior.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.36-47.
Abstract: This article contributes to the growing body of research that explores the significance of context in health information behavior. Specifically, through the lens of trust judgments, it demonstrates that gender is a determinant of the information evaluation process. A questionnaire-based survey collected data from adults regarding the factors that influence their judgment of the trustworthiness of online health information. Both men and women identified credibility, recommendation, ease of use, and brand as being of importance in their trust judgments. However, women also take into account style, while men eschew this for familiarity. In addition, men appear to be more concerned with the comprehensiveness and accuracy of the information, the ease with which they can access it, and its familiarity, whereas women demonstrate greater interest in cognition, such as the ease with which they can read and understand the information. These gender differences are consistent with the demographic data, which suggest that: women consult more types of sources than men; men are more likely to be searching with respect to a long-standing health complaint; and, women are more likely than men to use tablets in their health information seeking. Recommendations for further research to better inform practice are offered.
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23597/full.
26Kousha, K. ; Thelwall, M.: Patent citation analysis with Google.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.48-61.
Abstract: Citations from patents to scientific publications provide useful evidence about the commercial impact of academic research, but automatically searchable databases are needed to exploit this connection for large-scale patent citation evaluations. Google covers multiple different international patent office databases but does not index patent citations or allow automatic searches. In response, this article introduces a semiautomatic indirect method via Bing to extract and filter patent citations from Google to academic papers with an overall precision of 98%. The method was evaluated with 322,192 science and engineering Scopus articles from every second year for the period 1996-2012. Although manual Google Patent searches give more results, especially for articles with many patent citations, the difference is not large enough to be a major problem. Within Biomedical Engineering, Biotechnology, and Pharmacology & Pharmaceutics, 7% to 10% of Scopus articles had at least one patent citation but other fields had far fewer, so patent citation analysis is only relevant for a minority of publications. Low but positive correlations between Google Patent citations and Scopus citations across all fields suggest that traditional citation counts cannot substitute for patent citations when evaluating research.
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23608/full.
27Ren, Y. ; Tomko, M. ; Salim, F.D. ; Ong, K. ; Sanderson, M.: Analyzing Web behavior in indoor retail spaces.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.62-76.
Abstract: We analyze 18- million rows of Wi-Fi access logs collected over a 1-year period from over 120,000 anonymized users at an inner city shopping mall. The anonymized data set gathered from an opt-in system provides users' approximate physical location as well as web browsing and some search history. Such data provide a unique opportunity to analyze the interaction between people's behavior in physical retail spaces and their web behavior, serving as a proxy to their information needs. We found that (a) there is a weekly periodicity in users' visits to the mall; (b) people tend to visit similar mall locations and web content during their repeated visits to the mall; (c) around 60% of registered Wi-Fi users actively browse the web, and around 10% of them use Wi-Fi for accessing web search engines; (d) people are likely to spend a relatively constant amount of time browsing the web while the duration of their visit may vary; (e) the physical spatial context has a small, but significant, influence on the web content that indoor users browse; and (f) accompanying users tend to access resources from the same web domains.
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23587/full.
28Cleverley, P.H. ; Burnett, S. ; Muir, L.: Exploratory information searching in the enterprise : a study of user satisfaction and task performance.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.62-76.
Abstract: No prior research has been identified that investigates the causal factors for workplace exploratory search task performance. The impact of user, task, and environmental factors on user satisfaction and task performance was investigated through a mixed methods study with 26 experienced information professionals using enterprise search in an oil and gas enterprise. Some participants found 75% of high-value items, others found none, with an average of 27%. No association was found between self-reported search expertise and task performance, with a tendency for many participants to overestimate their search expertise. Successful searchers may have more accurate mental models of both search systems and the information space. Organizations may not have effective exploratory search task performance feedback loops, a lack of learning. This may be caused by management bias towards technology, not capability, a lack of systems thinking. Furthermore, organizations may not "know" they "don't know" their true level of search expertise, a lack of knowing. A metamodel is presented identifying the causal factors for workplace exploratory search task performance. Semistructured qualitative interviews with search staff from the defense, pharmaceutical, and aerospace sectors indicates the potential transferability of the finding that organizations may not know their search expertise levels.
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23595/full.
Themenfeld: Benutzerstudien ; Informationsdienstleistungen
29Zhitomirsky-Geffet, M. ; Prebor, G. ; Bloch, O.: Improving proverb search and retrieval with a generic multidimensional ontology.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.141-153.
Abstract: The goal of this research is to develop a generic ontological model for proverbs that unifies potential classification criteria and various characteristics of proverbs to enable their effective retrieval and large-scale analysis. Because proverbs can be described and indexed by multiple characteristics and criteria, we built a multidimensional ontology suitable for proverb classification. To evaluate the effectiveness of the constructed ontology for improving search and retrieval of proverbs, a large-scale user experiment was arranged with 70 users who were asked to search a proverb repository using ontology-based and free-text search interfaces. The comparative analysis of the results shows that the use of this ontology helped to substantially improve the search recall, precision, user satisfaction, and efficiency and to minimize user effort during the search process. A practical contribution of this work is an automated web-based proverb search and retrieval system which incorporates the proposed ontological scheme and an initial corpus of ontology-based annotated proverbs.
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23573/full.
Themenfeld: Automatisches Indexieren
30Hu, X. ; Lee, J.H. ; Bainbridge, D. ; Choi, K. ; Organisciak, P. ; Downie, J.S.: ¬The MIREX grand challenge : a framework of holistic user-experience evaluation in music information retrieval.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.97-112.
Abstract: Music Information Retrieval (MIR) evaluation has traditionally focused on system-centered approaches where components of MIR systems are evaluated against predefined data sets and golden answers (i.e., ground truth). There are two major limitations of such system-centered evaluation approaches: (a) The evaluation focuses on subtasks in music information retrieval, but not on entire systems and (b) users and their interactions with MIR systems are largely excluded. This article describes the first implementation of a holistic user-experience evaluation in MIR, the MIREX Grand Challenge, where complete MIR systems are evaluated, with user experience being the single overarching goal. It is the first time that complete MIR systems have been evaluated with end users in a realistic scenario. We present the design of the evaluation task, the evaluation criteria and a novel evaluation interface, and the data-collection platform. This is followed by an analysis of the results, reflection on the experience and lessons learned, and plans for future directions.
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23618/full.
31Rotolo, D. ; Rafols, I. ; Hopkins, M.M. ; Leydesdorff, L.: Strategic intelligence on emerging technologies : scientometric overlay mapping.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.214-233.
Abstract: This paper examines the use of scientometric overlay mapping as a tool of "strategic intelligence" to aid the governing of emerging technologies. We develop an integrative synthesis of different overlay mapping techniques and associated perspectives on technological emergence across geographical, social, and cognitive spaces. To do so, we longitudinally analyze (with publication and patent data) three case studies of emerging technologies in the medical domain. These are RNA interference (RNAi), human papillomavirus (HPV) testing technologies for cervical cancer, and thiopurine methyltransferase (TPMT) genetic testing. Given the flexibility (i.e., adaptability to different sources of data) and granularity (i.e., applicability across multiple levels of data aggregation) of overlay mapping techniques, we argue that these techniques can favor the integration and comparison of results from different contexts and cases, thus potentially functioning as a platform for "distributed" strategic intelligence for analysts and decision makers.
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23631/full.
32McNeese, N.J. ; Reddy, M.C.: ¬The role of team cognition in collaborative information seeking.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.129-140.
Abstract: Collaborative information seeking (CIS) is of growing importance in the information sciences and human-computer interaction (HCI) research communities. Current research has primarily focused on examining the social and interactional aspects of CIS in organizational or other settings and developing technical approaches to support CIS activities. As we continue to develop a better understanding of the interactional aspects of CIS, we need also start to examine the cognitive aspects of CIS. In particular, we need to understand CIS from a team cognition perspective. To examine how team cognition develops during CIS, we conducted a study using observations and interviews of student teams engaged in colocated CIS tasks in a laboratory setting. We found that a variety of awareness mechanisms play a key role in the development of team cognition during CIS. Specifically, we identify that search, information, and social methods of awareness are critical to developing team cognition during CIS. We discuss why awareness is important for team cognition, how team cognition comprises both individual and team-level cognitive activities, and the importance of examining both interaction and cognition to truly understand team cognition.
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23614/full.
33Hook, P.A.: Using course-subject Co-occurrence (CSCO) to reveal the structure of an academic discipline : a framework to evaluate different inputs of a domain map.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.182-196.
Abstract: This article proposes, exemplifies, and validates the use of course-subject co-occurrence (CSCO) data to generate topic maps of an academic discipline. A CSCO event is when 2 course-subjects are taught in the same academic year by the same teacher. A total of 61,856 CSCO events were extracted from the 2010-11 directory of the American Association of Law Schools and used to visualize the structure of law school education in the United States. Different normalization, ordination (layout), and clustering algorithms were compared and the best performing algorithm of each type was used to generate the final map. Validation studies demonstrate that CSCO produces topic maps that are consistent with expert opinion and 4 other indicators of the topical similarity of law school course-subjects. This research is the first to use CSCO to produce a visualization of a domain. It is also the first to use an expanded, multi-part gold standard to evaluate the validity of domain maps and the intermediate steps in their creation. It is suggested that the framework used herein may be adopted for other studies that compare different inputs of a domain map in order to empirically derive the best maps as measured against extrinsic sources of topical similarity (gold standards).
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23630/full.
34Aletras, N. ; Baldwin, T. ; Lau, J.H. ; Stevenson, M.: Evaluating topic representations for exploring document collections.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.154-167.
Abstract: Topic models have been shown to be a useful way of representing the content of large document collections, for example, via visualization interfaces (topic browsers). These systems enable users to explore collections by way of latent topics. A standard way to represent a topic is using a term list; that is the top-n words with highest conditional probability within the topic. Other topic representations such as textual and image labels also have been proposed. However, there has been no comparison of these alternative representations. In this article, we compare 3 different topic representations in a document retrieval task. Participants were asked to retrieve relevant documents based on predefined queries within a fixed time limit, presenting topics in one of the following modalities: (a) lists of terms, (b) textual phrase labels, and (c) image labels. Results show that textual labels are easier for users to interpret than are term lists and image labels. Moreover, the precision of retrieved documents for textual and image labels is comparable to the precision achieved by representing topics using term lists, demonstrating that labeling methods are an effective alternative topic representation.
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23574/full.
35Smith, C.L.: Investigating the role of semantic priming in query expression : a framework and two experiments.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.168-181.
Abstract: Modern search systems often meet their users' information needs, but when the system fails, searchers struggle to formulate effective queries. Query suggestions may help, but research suggests these often go unused. Although much is known about how searchers scan results pages when assessing relevance, little is known about the processes searchers use when struggling to reformulate queries. Investigating how searchers overcome query difficulties, and how search systems help and hinder that process, requires enquiry into the cognitive procedures searchers use to select words for queries. The purpose of this paper is to investigate one cognitive process involved: semantic priming of words in memory. A framework for conceptualizing the role of semantic priming in search interaction is presented, along with results from two experiments that applied research methods from cognitive psychology, in an investigation of word selection and subsequent search for selected words. The results show that word selection activates related words in memory and that looking for a selected word among related words is effortful. The finding suggests that semantic priming may play a role in the difficulties people experience when reformulating queries. Ideas for continued development of semantic priming methods and their use in future research are also presented.
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23611/full.
36Leydesdorff, L. ; Nooy, W. de: Can "hot spots" in the sciences be mapped using the dynamics of aggregated journal-journal citation relations.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.197-213.
Abstract: Using 3 years of the Journal Citation Reports (2011, 2012, and 2013), indicators of transitions in 2012 (between 2011 and 2013) were studied using methodologies based on entropy statistics. Changes can be indicated at the level of journals using the margin totals of entropy production along the row or column vectors, but also at the level of links among journals by importing the transition matrices into network analysis and visualization programs (and using community-finding algorithms). Seventy-four journals were flagged in terms of discontinuous changes in their citations, but 3,114 journals were involved in "hot" links. Most of these links are embedded in a main component; 78 clusters (containing 172 journals) were flagged as potential "hot spots" emerging at the network level. An additional finding was that PLoS ONE introduced a new communication dynamic into the database. The limitations of the methodology were elaborated using an example. The results of the study indicate where developments in the citation dynamics can be considered as significantly unexpected. This can be used as heuristic information, but what a "hot spot" in terms of the entropy statistics of aggregated citation relations means substantively can be expected to vary from case to case.
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23634/full.
37Vinkler, P.: Core indicators and professional recognition of scientometricians.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.234-242.
Abstract: The publication performance of 30 scientometricians is studied. The individuals are classified into 3 cohorts according to their manifested professional recognition, as Price medalists (Pm), members of the editorial board of Scientometrics and the Journal of Informetrics (Rw), and session chairs (Sc) at an International Society of Scientometrics and Informetrics (ISSI) conference. Several core impact indicators are calculated: h, g, p, citation distribution score (CDS), percentage rank position (PRP), and weight of influence of papers (WIP10). The indices significantly correlate with each other. The mean value of the indices of the cohorts decreases parallel with the decrease in professional recognition: Pm?>?Rw?>?Sc. The 30 scientometricians studied were clustered according to the core impact indices. The members in the clusters so obtained overlap only partly with the members in the cohorts made by professional recognition. The Total Overlap is calculated by dividing the sum of the diagonal elements in the cohorts-clusters matrix with the total number of elements, times 100. The highest overlap (76.6%) was obtained with the g-index. Accordingly, the g-index seems to have the greatest discriminative power in the system studied. The cohorts-clusters method may be used for validating scientometric indicators.
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23589/full.
38Kocher, M. ; Savoy, J.: ¬A simple and efficient algorithm for authorship verification.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.259-269.
Abstract: This paper describes and evaluates an unsupervised and effective authorship verification model called Spatium-L1. As features, we suggest using the 200 most frequent terms of the disputed text (isolated words and punctuation symbols). Applying a simple distance measure and a set of impostors, we can determine whether or not the disputed text was written by the proposed author. Moreover, based on a simple rule we can define when there is enough evidence to propose an answer or when the attribution scheme is unable to make a decision with a high degree of certainty. Evaluations based on 6 test collections (PAN CLEF 2014 evaluation campaign) indicate that Spatium-L1 usually appears in the top 3 best verification systems, and on an aggregate measure, presents the best performance. The suggested strategy can be adapted without any problem to different Indo-European languages (such as English, Dutch, Spanish, and Greek) or genres (essay, novel, review, and newspaper article).
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23648/full.
39Guerci Sidone, O.J. ; Haddad, E.A. ; Mena-Chalco, J.P.: Scholarly publication and collaboration in Brazil : the role of geography.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.243-258.
Abstract: Brazilian scholarly output has rapidly increased, accompanied by the expansion of domestic collaborations. In this paper, we identify spatial patterns of collaboration in Brazil and measure the role of geographic proximity in determining the interaction among researchers. Using a database comprising more than one million researchers and seven million publications, we consolidated information on interregional research collaboration in terms of scientific coauthorship networks among 4,615 municipalities during the period between 1992 and 2009, which allowed us to analyze a range of data unprecedented in the literature. The effects of geographic distance on collaboration were measured for different areas by estimating spatial interaction models. The main results provide strong evidence of geographic deconcentration of collaboration in recent years, with increased participation of authors in scientifically less traditional regions, such as south and northeast Brazil. Distance remains a significant factor in determining the intensity of knowledge flow in collaboration networks in Brazil, as an increase of 100?km between two researchers reduces the probability of collaboration by an average of 16%, and there is no evidence that the effect of distance has diminished over time, although the magnitude of such effects varies among networks of different areas.
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23635/full.
40Pontis, S. ; Blandford, A. ; Greifeneder, E. ; Attalla, H. ; Neal, D.: Keeping up to date : an academic researcher's information journey.
In: Journal of the Association for Information Science and Technology. 67(2017) no.1, S.22-35.
Abstract: Keeping up to date with research developments is a central activity of academic researchers, but researchers face difficulties in managing the rapid growth of available scientific information. This study examined how researchers stay up to date, using the information journey model as a framework for analysis and investigating which dimensions influence information behaviors. We designed a 2-round study involving semistructured interviews and prototype testing with 61 researchers with 3 levels of seniority (PhD student to professor). Data were analyzed following a semistructured qualitative approach. Five key dimensions that influence information behaviors were identified: level of seniority, information sources, state of the project, level of familiarity, and how well defined the relevant community is. These dimensions are interrelated and their values determine the flow of the information journey. Across all levels of professional expertise, researchers used similar hard (formal) sources to access content, while soft (interpersonal) sources were used to filter information. An important "pain point" that future information tools should address is helping researchers filter information at the point of need.
Inhalt: Vgl.: http://onlinelibrary.wiley.com/doi/10.1002/asi.23623/full.
Themenfeld: Suchtaktik ; Informationsdienstleistungen