Search (3 results, page 1 of 1)

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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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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.

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Abstract

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.