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Jun, W.: ¬A knowledge network constructed by integrating classification, thesaurus and metadata in a digital library (2003)
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- Abstract
- Knowledge management in digital libraries is a universal problem. Keyword-based searching is applied everywhere no matter whether the resources are indexed databases or full-text Web pages. In keyword matching, the valuable content description and indexing of the metadata, such as the subject descriptors and the classification notations, are merely treated as common keywords to be matched with the user query. Without the support of vocabulary control tools, such as classification systems and thesauri, the intelligent labor of content analysis, description and indexing in metadata production are seriously wasted. New retrieval paradigms are needed to exploit the potential of the metadata resources. Could classification and thesauri, which contain the condensed intelligence of generations of librarians, be used in a digital library to organize the networked information, especially metadata, to facilitate their usability and change the digital library into a knowledge management environment? To examine that question, we designed and implemented a new paradigm that incorporates a classification system, a thesaurus and metadata. The classification and the thesaurus are merged into a concept network, and the metadata are distributed into the nodes of the concept network according to their subjects. The abstract concept node instantiated with the related metadata records becomes a knowledge node. A coherent and consistent knowledge network is thus formed. It is not only a framework for resource organization but also a structure for knowledge navigation, retrieval and learning. We have built an experimental system based on the Chinese Classification and Thesaurus, which is the most comprehensive and authoritative in China, and we have incorporated more than 5000 bibliographic records in the computing domain from the Peking University Library. The result is encouraging. In this article, we review the tools, the architecture and the implementation of our experimental system, which is called Vision.
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Koopman, B.; Zuccon, G.; Bruza, P.; Sitbon, L.; Lawley, M.: Information retrieval as semantic inference : a graph Inference model applied to medical search (2016)
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- Abstract
- This paper presents a Graph Inference retrieval model that integrates structured knowledge resources, statistical information retrieval methods and inference in a unified framework. Key components of the model are a graph-based representation of the corpus and retrieval driven by an inference mechanism achieved as a traversal over the graph. The model is proposed to tackle the semantic gap problem-the mismatch between the raw data and the way a human being interprets it. We break down the semantic gap problem into five core issues, each requiring a specific type of inference in order to be overcome. Our model and evaluation is applied to the medical domain because search within this domain is particularly challenging and, as we show, often requires inference. In addition, this domain features both structured knowledge resources as well as unstructured text. Our evaluation shows that inference can be effective, retrieving many new relevant documents that are not retrieved by state-of-the-art information retrieval models. We show that many retrieved documents were not pooled by keyword-based search methods, prompting us to perform additional relevance assessment on these new documents. A third of the newly retrieved documents judged were found to be relevant. Our analysis provides a thorough understanding of when and how to apply inference for retrieval, including a categorisation of queries according to the effect of inference. The inference mechanism promoted recall by retrieving new relevant documents not found by previous keyword-based approaches. In addition, it promoted precision by an effective reranking of documents. When inference is used, performance gains can generally be expected on hard queries. However, inference should not be applied universally: for easy, unambiguous queries and queries with few relevant documents, inference did adversely affect effectiveness. These conclusions reflect the fact that for retrieval as inference to be effective, a careful balancing act is involved. Finally, although the Graph Inference model is developed and applied to medical search, it is a general retrieval model applicable to other areas such as web search, where an emerging research trend is to utilise structured knowledge resources for more effective semantic search.
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Layfield, C.; Azzopardi, J,; Staff, C.: Experiments with document retrieval from small text collections using Latent Semantic Analysis or term similarity with query coordination and automatic relevance feedback (2017)
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- Series
- Information Systems and Applications, incl. Internet/Web, and HCI; 10151
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Zhang, J.; Mostafa, J.; Tripathy, H.: Information retrieval by semantic analysis and visualization of the concept space of D-Lib® magazine (2002)
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- Abstract
- In this article we present a method for retrieving documents from a digital library through a visual interface based on automatically generated concepts. We used a vocabulary generation algorithm to generate a set of concepts for the digital library and a technique called the max-min distance technique to cluster them. Additionally, the concepts were visualized in a spring embedding graph layout to depict the semantic relationship among them. The resulting graph layout serves as an aid to users for retrieving documents. An online archive containing the contents of D-Lib Magazine from July 1995 to May 2002 was used to test the utility of an implemented retrieval and visualization system. We believe that the method developed and tested can be applied to many different domains to help users get a better understanding of online document collections and to minimize users' cognitive load during execution of search tasks. Over the past few years, the volume of information available through the World Wide Web has been expanding exponentially. Never has so much information been so readily available and shared among so many people. Unfortunately, the unstructured nature and huge volume of information accessible over networks have made it hard for users to sift through and find relevant information. To deal with this problem, information retrieval (IR) techniques have gained more intensive attention from both industrial and academic researchers. Numerous IR techniques have been developed to help deal with the information overload problem. These techniques concentrate on mathematical models and algorithms for retrieval. Popular IR models such as the Boolean model, the vector-space model, the probabilistic model and their variants are well established.
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Ingwersen, P.; Järvelin, K.: ¬The turn : integration of information seeking and retrieval in context (2005)
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- Footnote
- - Kapitel fünf enthält einen entsprechenden Überblick über die kognitive und benutzerorientierte IR-Tradition. Es zeigt, welche anderen (als nur die labororientierten) IR-Studien durchgeführt werden können, wobei sich die Betrachtung von frühen Modellen (z.B. Taylor) über Belkins ASK-Konzept bis zu Ingwersens Modell der Polyrepräsentation, und von Bates Berrypicking-Ansatz bis zu Vakkaris "taskbased" IR-Modell erstreckt. Auch Web-IR, OKAPI und Diskussionen zum Relevanzbegriff werden hier thematisiert. - Im folgenden Kapitel schlagen die Autoren ein integriertes IS&R Forschungsmodell vor, bei dem die vielfältigen Beziehungen zwischen Informationssuchenden, Systementwicklern, Oberflächen und anderen beteiligten Aspekten berücksichtigt werden. Ihr Ansatz vereint die traditionelle Laborforschung mit verschiedenen benutzerorientierten Traditionen aus IS&R, insbesondere mit den empirischen Ansätzen zu IS und zum interaktiven IR, in einem holistischen kognitiven Modell. - Kapitel sieben untersucht die Implikationen dieses Modells für IS&R, wobei besonders ins Auge fällt, wie komplex die Anfragen von Informationssuchenden im Vergleich mit der relativen Einfachheit der Algorithmen zum Auffinden relevanter Dokumente sind. Die Abbildung der vielfältig variierenden kognitiven Zustände der Anfragesteller im Rahmen der der Systementwicklung ist sicherlich keine triviale Aufgabe. Wie dabei das Problem der Einbeziehung des zentralen Aspektes der Bedeutung gelöst werden kann, sei dahingestellt. - Im achten Kapitel wird der Versuch unternommen, die zuvor diskutierten Punkte in ein IS&R-Forschungsprogramm (Prozesse - Verhalten - Systemfunktionalität - Performanz) umzusetzen, wobei auch einige kritische Anmerkungen zur bisherigen Forschungspraxis getroffen werden. - Das abschliessende neunte Kapitel fasst das Buch kurz zusammen und kann somit auch als Einstieg in dieThematik gelesen werden. Darauffolgen noch ein sehr nützliches Glossar zu allen wichtigen Begriffen, die in dem Buch Verwendung finden, eine Bibliographie und ein Sachregister. Ingwersen und Järvelin haben hier ein sehr anspruchsvolles und dennoch lesbares Buch vorgelegt. Die gebotenen Übersichtskapitel und Diskussionen sind zwar keine Einführung in die Informationswissenschaft, decken aber einen grossen Teil der heute in dieser Disziplin aktuellen und durch laufende Forschungsaktivitäten und Publikationen berührten Teilbereiche ab. Man könnte es auch - vielleicht ein wenig überspitzt - so formulieren: Was hier thematisiert wird, ist eigentlich die moderne Informationswissenschaft. Der Versuch, die beiden Forschungstraditionen zu vereinen, wird diesem Werk sicherlich einen Platz in der Geschichte der Disziplin sichern. Nicht ganz glücklich erscheint der Titel des Buches. "The Turn" soll eine Wende bedeuten, nämlich jene hin zu einer integrierten Sicht von IS und IR. Das geht vermutlich aus dem Untertitel besser hervor, doch dieser erschien den Autoren wohl zu trocken. Schade, denn "The Turn" gibt es z.B. in unserem Verbundkatalog bereits, allerdings mit dem Zusatz "from the Cold War to a new era; the United States and the Soviet Union 1983-1990". Der Verlag, der abgesehen davon ein gediegenes (wenn auch nicht gerade wohlfeiles) Produkt vorgelegt hat, hätte derlei unscharfe Duplizierend besser verhindert. Ungeachtet dessen empfehle ich dieses wichtige Buch ohne Vorbehalt zur Anschaffung; es sollte in keiner grösseren Bibliothek fehlen."
