Restricted inflectional form generation in management of morphological keyword variation     

Kimmo Kettunen  Eija Airio  Kalervo Järvelin 《Information Retrieval》2007,10(4-5):415-444

Word form normalization through lemmatization or stemming is a standard procedure in information retrieval because morphological variation needs to be accounted for and several languages are morphologically non-trivial. Lemmatization is effective but often requires expensive resources. Stemming is also effective in most contexts, generally almost as good as lemmatization and typically much less expensive; besides it also has a query expansion effect. However, in both approaches the idea is to turn many inflectional word forms to a single lemma or stem both in the database index and in queries. This means extra effort in creating database indexes. In this paper we take an opposite approach: we leave the database index un-normalized and enrich the queries to cover for surface form variation of keywords. A potential penalty of the approach would be long queries and slow processing. However, we show that it only matters to cover a negligible number of possible surface forms even in morphologically complex languages to arrive at a performance that is almost as good as that delivered by stemming or lemmatization. Moreover, we show that, at least for typical test collections, it only matters to cover nouns and adjectives in queries. Furthermore, we show that our findings are particularly good for short queries that resemble normal searches of web users. Our approach is called FCG (for Frequent Case (form) Generation). It can be relatively easily implemented for Latin/Greek/Cyrillic alphabet languages by examining their (typically very skewed) nominal form statistics in a small text sample and by creating surface form generators for the 3–9 most frequent forms. We demonstrate the potential of our FCG approach for several languages of varying morphological complexity: Swedish, German, Russian, and Finnish in well-known test collections. Applications include in particular Web IR in languages poor in morphological resources.  相似文献   

Dictionary-Based Cross-Language Information Retrieval: Learning Experiences from CLEF 2000–2002     

Turid Hedlund  Eija Airio  Heikki Keskustalo  Raija Lehtokangas  Ari Pirkola  Kalervo Järvelin 《Information Retrieval》2004,7(1-2):99-119

In this study the basic framework and performance analysis results are presented for the three year long development process of the dictionary-based UTACLIR system. The tests expand from bilingual CLIR for three language pairs Swedish, Finnish and German to English, to six language pairs, from English to French, German, Spanish, Italian, Dutch and Finnish, and from bilingual to multilingual. In addition, transitive translation tests are reported. The development process of the UTACLIR query translation system will be regarded from the point of view of a learning process. The contribution of the individual components, the effectiveness of compound handling, proper name matching and structuring of queries are analyzed. The results and the fault analysis have been valuable in the development process. Overall the results indicate that the process is robust and can be extended to other languages. The individual effects of the different components are in general positive. However, performance also depends on the topic set and the number of compounds and proper names in the topic, and to some extent on the source and target language. The dictionaries used affect the performance significantly.  相似文献   

How Effective is Stemming and Decompounding for German Text Retrieval?     

Martin Braschler  Bärbel Ripplinger 《Information Retrieval》2004,7(3-4):291-316

Information retrieval systems operating on free text face difficulties when word forms used in the query and documents do not match. The usual solution is the use of a “stemming component” that reduces related word forms to a common stem. Extensive studies of such components exist for English, but considerably less is known for other languages. Previously, it has been claimed that stemming is essential for highly declensional languages. We report on our experiments on stemming for German, where an additional issue is the handling of compounds, which are formed by concatenating several words. The major contribution of our work that goes beyond its focus on German lies in the investigation of a complete spectrum of approaches, ranging from language-independent to elaborate linguistic methods. The main findings are that stemming is beneficial even when using a simple approach, and that carefully designed decompounding, the splitting of compound words, remarkably boosts performance. All findings are based on a thorough analysis using a large reliable test collection.  相似文献   

Book reviews     

Herbert Berg  Joseph Cremona  Hadia Dajani‐Shakeel  Michael Gervers  Colin Smith  Heather L. Ecker 《Al-Masaq: Islam & the Medieval Mediterranean》1994,7(1):279-331

Mir, Mustansir. Verbal Idioms of the Qur'ān. (Michigan Series on the Middle East, no. I). Ann Arbon University of Michigan, 1989. xxi+378 pp., glossary; US$ 21.95 (paperback).

Fiotini, Stanley and Mallia‐Milanes, Victor, eds. Malta. A Case Study in International Cross‐Currents. Proceedings of the First International Colloquium on the History of the Central Mediterranean held at the University of Malta, 13–17 December 1989. Msida: Malta University Publications, 1991. xxii+300pp. 17 plates, 8 text figures. M£5.

Bellamy, James A. ed. Studies in Near Eastern Culture and History in Memory of Ernest T. Abdel‐Massih. (Michigan Series on the Middle East, no. 2). Ann Arbor: The University of Michigan, 1990. x+225pp.

Dajani‐Shakeel, Hadia and Messier, Ronald A. eds. The Jihād and its Times, dedicated to Andrew Stefan Ehrenkreutz. Ann Arbor: Center for Near Eastern and North African Studies, The University of Michigan, 1991. iii+135pp.

Minorités religieuses dans l'Espagne médiévale. (Nos. 63–64 of Revue du Monde Musulman et de la Méditerranée). Aix‐en‐Provence: Édisud, 1992. FF 160.

Burckhardt, Titus. Fez, City of Islam. Translated by William Stoddart. Cambridge: Islamic Texts Society, 1992. 175pp. 58pl.

Jayyusi, Salma Kh., ed. The Legacy of Muslim Spain. Leiden: Brill, 1992. (Handbuch der Orientalistik, Erste Abteilung, The Near and Middle East, zwolfter Band), xix+1098 pp. 6 maps; 27 pages of colour and black and white illustrations. Hfl. 450.

Stetkevych, Jaroslav. The Zephyrs of Najd: The Poetics of Nostalgia in the Classical Arabic Nasib. Chicago: University of Chicago Press, 1993. xii+326pp.

Corbin, Henry. History of Islamic Philosophy. London: Kegan Paul International/Islamic Publications for The Institute of Ismaili Studies, 1993. xvii+445pp. £55.

Burrell, David B., C.S.C. Freedom and Creation in Three Traditions. Notre Dame, Indiana: University of Notre Dame Press, 1993. xi, 225 pp. Cloth $29.95; paper $13.95.

Köprülü, Mehmed Fuad. Islam in Anatolia after the Turkish Invasion. Translated and edited by Gary Leiser. Salt Lake City: University of Utah Press, 1993. xviii, 141pp.

Stetkevych, Suzanne Pinckney. The Mute Immortals Speak: Pre‐Islamic Poetry and the Poetics of Ritual (Myth and Poetics. Gen. ed. Gregory Nagy). Ithaca and London: Cornell University Press, 1993. xvi, 334pp.; appendix of Arabic texts.

L'Expulsió dels Moriscos. Conseqüències en el món islàmic i el món cristià. Sant Caries de la Ràpita 5–9 de desembre de 1990. Barcelona: Generalitat de Catalunya, Departament de Cultura, 1994. 418pp.

Agius, Dionisius A. and Hitchcock, Richard, eds. The Arab Influence in Medieval Europe (Folia Scholastica Mediterranean Reading: Ithaca Press, 1994. 167pp. £30.

Davidson, Olga M. Poet and Hero in the Persian Book of Kings (Myth and Poetics. Gen. ed. Gregory Nagy). Ithaca and London: Cornell University Press, 1994. xi, 197pp.  相似文献   

Pricing and other means of charging for scholarly journals: a literature review and commentary     

Donald W. KING  Frances M. ALVARADO‐ALBERTORIO 《Learned Publishing》2008,21(4):248-272

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The process of conceptual change in force and motion during computer‐supported physics instruction     

Ping‐Kee Tao  Richard F. Gunstone 《科学教学研究杂志》1999,36(7):859-882

The process of students' conceptual change was investigated during a computer‐supported physics unit in a Grade 10 science class. Computer simulation programs were developed to confront students' alternative conceptions in mechanics. A conceptual test was administered as a pre‐, post‐, and delayed posttest to determine students' conceptual change. Students worked collaboratively in pairs on the programs carrying out predict–observe–explain tasks according to worksheets. While the pairs worked on the tasks, their conversational interactions were recorded. A range of other data was collected at various junctures during instruction. At each juncture, the data for each of 12 students were analyzed to provide a conceptual snapshot at that juncture. All the conceptual snapshots together provided a delineation of the students' conceptual development. It was found that many students vacillated between alternative and scientific conceptions from one context to another during instruction, i.e., their conceptual change was context dependent and unstable. The few students who achieved context independent and stable conceptual change appeared to be able to perceive the commonalities and accept the generality of scientific conceptions across contexts. These findings led to a pattern of conceptual change which has implications for instructional practices. The article concludes with consequent implications for classsrooms. © 1999 John Wiley & Sons, Inc. J Res Sci Teach 36: 859–882, 1999  相似文献   

Interpretations of graphs by university biology students and practicing scientists: Toward a social practice view of scientific representation practices     

G. Michael Bowen  Wolff‐Michael Roth  Michelle K. McGinn 《科学教学研究杂志》1999,36(9):1020-1043

Using graphs is a key social practice of professional science. As part of a research program that investigates the development of graphing practices from elementary school to professional science activities, this study was designed to investigate similarities and differences in graph‐related interpretations between scientists and college students engaged in collective graph interpretation. Forty‐five students in a second‐year university ecology course and four scientists participated in the study. Guided by domain‐ specific concerns, scientists' graph‐related activities were characterized by a large number of experience‐based, domain‐specific interpretive resources and practices. Students' group based activities were characterized by the lack of linguistic distinctions (between scientific terms) which led to ambiguities in group negotiations; there was also a lack of knowledge about specific organism populations which helped field ecologists construct meaning. Many students learned to provide correct answers to specific graphing questions but did not come to make linguistic distinctions or increase their knowledge of specific populations. In the absence of concerns other than to do well in the course, students did not appear to develop any general interpretive skills for graphs, but learned instead to apply the professor's interpretation. This is problematic because, as we have demonstrated, there are widely differing viable interpretations of the graph. Suggestions for changes in learning environments for graphing that should alleviate this problem are made. © 1999 John Wiley & Sons, Inc. J Res Sci Teach 36: 1020–1043, 1999  相似文献   

Navigating Uncertainty: Early Career Academics and Practices of Appraisal Devices     

Nästesjö  Jonatan 《Minerva》2021,59(2):237-259

Minerva - There is a lack of objective evaluative standards for academic work. While this has been recognized in studies of how gatekeepers pass judgment on the works of others, little is known...  相似文献   

Identity and Culture: theorising emergent environmentalism     

Justin Dillon  Elin Kelsey  Ana Maria Duque‐Aristizabal 《Environmental Education Research》1999,5(4):395-405

This article critically examines the methodology and findings of the emergent environmentalism research project as reported in Environmental Education Research (EER), 4(4). We challenge both the ontological stance implicit in the research as well as its explicit epistemology. We argue for a wider theoretical underpinning to the research and specifically advocate the use of identity theories to explain personal and social phenomena. We also argue for the use of theoretical frameworks that empower rather than ‘capture’ cultural groups.  相似文献   

The Effects of Conjunction, Facet Structure, and Dictionary Combinations in Concept-Based Cross-Language Retrieval   总被引：1，自引：1，他引：0  

Ari Pirkola  Heikki Keskustalo  Kalervo Järvelin 《Information Retrieval》1999,1(3):217-250

The paper studies concept-based cross-language information retrieval (CLIR). The document collection was a subset of the TREC collection. The test requests were formed from TREC's health related topics. As translation dictionaries the study used a general dictionary and a domain-specific (=medical) dictionary. The effects of translation method, conjunction, and facet order on the effectiveness of concept-based cross-language queries were studied, and concept-based structuring of cross-language queries was compared to mechanical structuring based on the output of dictionaries. The performance of translated Finnish queries against English documents was compared to the performance of original English queries against the English documents, and the performance of different CLIR query types was compared with one another. No major difference was found between concept-based and mechanical structuring. The best translation method was a simultaneous look-up in the medical dictionary and the general dictionary, in which case cross-language queries performed as well as the original English queries. The results showed that especially at high exhaustivity (the number of mutually restrictive concepts in a request) levels cross-language queries perform well in relation to monolingual queries. This suggests that conjunction disambiguates cross-language queries. An extensive study was made of the relative importance of the concepts of requests. On the basis of the classification data of request concepts it was shown how the order of facets in a query affects cross-language as well as monolingual queries.  相似文献