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Principles of Searching © Tefko Saracevic1 La búsqueda en la web & la web invisible Buscando lo difícil de buscar.

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Presentación del tema: "Principles of Searching © Tefko Saracevic1 La búsqueda en la web & la web invisible Buscando lo difícil de buscar."— Transcripción de la presentación:

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2 Principles of Searching © Tefko Saracevic1 La búsqueda en la web & la web invisible Buscando lo difícil de buscar

3 Principles of Searching © Tefko Saracevic2 Definiciones de diccionario World wide web : Archivos conectados a través de Internet Enorme conjunto de documentos y otros archivos enlazados localizados en ordenadores conectados a través de Internet y utilizados para acceder, manipular, y descargar datos y programas Invisible - Definición de diccionario: Que no puede ser visto Web Invisible– No está en el diccionario

4 Principles of Searching © Tefko Saracevic3

5 Principles of Searching © Tefko Saracevic4 What is Invisible web? Materiales que no incluyen, o no quieren incluir, los buscadores generales en su colección de páginas web (índices) Inencontrables a través de los buscadores generales Contiene una enorme cantidad de recursos de información En buena medida de mayor calidad y autoridad que la de la web visible La calidad es su principal característica Especializada Parte de ella fluye, o está en streaming o en tiempo real No puedes bañarte dos veces en el mismo río Parte de ella gratuita Mucho más extensa que la Web visible

6 Principles of Searching © Tefko Saracevic5 en otras palabras… Hay mucho más en la web que o

7 Principles of Searching © Tefko Saracevic6 ¿Porqué los buscadores no cubren todo? Tamaño: La web es enorme, no pueden abarcarlo todo Factores Económicos: Los costes asociados son altos Los buscadores viven de la publicidad Cierto número de buscadores ofrecen resultados de pago FactoresTécnicos: Capacidad limitada Algunos formatos de archivo son difíciles de tratar Spam: Eliminan lo malo pero se puede perder lo bueno Restricciones: Algunos sitios no permiten acceso a los buscadores Estructura profunda : Algunos sitios son complejos

8 Principles of Searching © Tefko Saracevic7 Cómo trabajan los buscadores? Crawlers, spiders: buscan contenido Localizan sitios nuevos o modificados De maneras periódica, no en cada búsqueda Ningún buscador trabaja en tiempo real (salvo Gnews) Organización de contenido: etiquetado, ordenación Indización para búsquedas o clasificación en directorios Bases de Datos, cachés: almacenamiento de contenidos Motor de búsqueda: en función de las demandas Interface: petición de búsqueda, visualización de resultados Todo ello basado en algoritmos varios, habitualmente ocultos o secretos

9 Principles of Searching © Tefko Saracevic8 Cobertura de los buscadores No cubren más allá de un 20% Difícil (imposible) discernir & comparar cobertura Buscadores nacionales Cobertura y orientación propia Muchos buscadores especializados Cobertura propia hacia un tema de interés Fuentes independientes de material útil Recopilaciones de recursos evaluados

10 Principles of Searching © Tefko Saracevic9 Los buscadores difieren Hay diferencias muy importantes entre los tipos de buscadores citados Necesidad de saber cómo funcionan y en qué difieren Información sobre buscadores : Search Engine Watch ratings, news, statistics, charts, explanations, tutorials Search Engine Showdown The users guide to web searching - run by a librarian, news links, ratings

11 Principles of Searching © Tefko Saracevic10 Búsqueda en la web Invisible : Datos básicos Primer paso: Saber claramente qué estás buscando. Limitar la búsqueda a recursos y herramientas apropiadas al tipo de información que estás buscando Conocer las fuentes Saber encontrar fuentes

12 Principles of Searching © Tefko Saracevic11 Fuentes especializadas - en la web invisible 1. Meta buscadores 2. Buscadores y catálogos especializados 3. Buscadores y catálogos temáticos 4. Fuentes de referencia 5. Bibliotecas 6. Bibliotecas virtuales 7. Bases de datos especialiuzadas 8. Sociedades, organizaciones 9. Libros!!!

13 Principles of Searching © Tefko Saracevic12 Metabuscadores Metabuscadores buscan en otros B. Combiando resultados Dónde encontrar buscadores o metabuscadores: SearchEngines.com search for engines by topic, geography, reference Search Engine Guide engines categorized by topic; other engine information Search Engine Colossus international directory of search engines by country, topic from 198 countries and 61 territories; engines in choice of languages

14 Principles of Searching © Tefko Saracevic13 Sample of meta engines Some meta engines provide organized results: Dogpile results from a number of leading search engines; gives source, so overlap can be compared; (has also a (bad) joke of the day) Surfwax gives statistics and text sources & linking to sources; for some terms gives related terms to focus Teoma results with suggestions for narrowing; links resources derived; originated at Rutgers Turbo10 provides results in clusters; engines searched can be edited

15 Principles of Searching © Tefko Saracevic14 meta search engines (cont.) Large directory Complete Planet directory of over 70,000 databases & specialty engines Results with graphical displays Vivisimo clusters results; innovative Webbrain results in tree structure – fun to use Kartoo results in display by topics of query

16 Principles of Searching © Tefko Saracevic15 Domain engines & catalogs Cover general & specific subjects Open Directory Project large edited catalog of the web – global, run by volunteers BUBL LINK selected Internet resources covering all academic subject areas; organized by Dewey Decimal System – from UK Profusion search in categories for resources & search engines Resource Discovery Network Resource Discovery Network – UK UK's free national gateway to Internet resources for the learning, teaching and research community

17 Principles of Searching © Tefko Saracevic16 domain engines … Available in variety of domains & subjects – rich! Think Quest – Oracle Education Foundation Think Quest education resources, programs; web sites created by students All Music Guide resource about musicians, albums, and songs Internet Movie Database treasure trove of American and British movies Genealogy links and surname search engines well.. that is getting really specialized (and popular)

18 Principles of Searching © Tefko Saracevic17 domain engines … Scholarship, science Psychcrawler - Amer Psychological Association Psychcrawler web index for psychology Entrez PubMed – Nat Library of Medicine Entrez PubMed biomedical literature from MEDLINE & health journals CiteSeer - NEC Research Center CiteSeer scientific literature, citations index; strong in computer science Scholar Google searches for scholarly articles & resources Infomine scholarly internet research collections

19 Principles of Searching © Tefko Saracevic18 Reference services Reference services - several models Q&A, directories, answers etc. Ask Jeeves! most popular, commercial Information Please almanac type questions RefDesk access to a number of reference tools Wikipedia web encyclopedia in many languages

20 Principles of Searching © Tefko Saracevic19 reference … Digital reference - new service area for libraries QuestionPoint L of Congress & OCLC QuestionPoint project for a global reference network Virtual Reference Desk – L of Congress Virtual Reference Desk large compilation of web reference sites LiveRef - maintained at Iowa State U LiveRef a registry of real time digital reference services

21 Principles of Searching © Tefko Saracevic20 Libraries as web sources Academic, national libraries providing open collections & services; models vary Rutgers libraries - big long term effort Rutgers libraries University of California, Berkeley a most elaborate effort together with Sun Corporation LibWebLibWeb U California, Berkeley lists currently over 7200pages from libraries in over 125 countries Bibliothèque Nationale de France includes virtual exhibitions, among others

22 Principles of Searching © Tefko Saracevic21 Virtual libraries on the Web Libraries emerging only on the Web Virtual Library –Virtual Library Switzerland, US, UK & other countries – oldest virtual library on the Web Internet Public Library U of Michigan Internet Public Library also a long term effort Librarians Index of the Internet very popular and comprehensive Digital librarian a librarian's choice of the best of the Web – compiled and annotated by a librarian

23 Principles of Searching © Tefko Saracevic22 virtual libraries … Academic Info Digital Library many links to digital collections & resources in various subjects Gabriel Gateway to European National Libraries Museum of online museums a delight Stanford Encyclopedia of Philosophy a comprehensive encyclopedia and library The historical New York Times Project universal library – ongoing digitization

24 Principles of Searching © Tefko Saracevic23 Subjects resources Many subject specific sites rich & often unique coverage & services different approaches & requirements Examples in health related domains: WebMDHealth news, medical information Rxlist The Internet Drug Index Mayo Clinic HealthOasis health advice Kidshealth sites for parents, kids, teens

25 Principles of Searching © Tefko Saracevic24 Subject resources … Scholarship, humanities, government KIRKE - Katalog der Internetressourcen für die Klassische Philologie aus Erlangen KIRKE German; a variety of resources for classics Perseus Digital Library Tufts University Perseus Digital Library covers antiquity to renaissance; one of the best subject sites on the web; affected the whole field Sch of Slavonic & East European Studies, University College London Sch of Slavonic & East European Studies includes country resources, e.g. Croatia U Mich Document Center official documents from all over the world

26 Principles of Searching © Tefko Saracevic25 Subject resources … Growing number of resources in arts, museums MuseumStuff.com We have 1000's of museums, zoos, historical societies and related organizations in our database The State Hermitage Museum One of the greatest museums in the world, and one of the best museum site – developed with IBM help National Museum of Science and Technology Leonardo da Vinci Guess where those pictures came from. A delight!

27 Principles of Searching © Tefko Saracevic26 subject resources … Diotima Materials for study of women and gender in the Ancient World Moving Images Collections MIC documents moving image collections around the world. Part particularly oriented toward science educators. Now at Library of Congress, but developed at Rutgers. And, of course … Snoopy The Official Peanuts Website

28 Principles of Searching © Tefko Saracevic27 Societies, organizations Many societies, agencies developed their sites great many rich sources for searching & resources differences in requirements, depth, richness Assoc. for Computing Machinery Digital Library; subscription or registration or through RUL US State Department about the U.S & other countries FirstGov the US government official web portal Ocean Planet Ocean Planet NASA presentation of earth & its vast oceans ArXivArXiv Cornell U, National Science Foundation e-print service in the fields of physics, mathematics, non- linear science, computer science, and quantitative biology

29 Principles of Searching © Tefko Saracevic28 Archiving, books on the web Internet Archive – a large undertaking Internet Archive includes web archive & lots more publicly available & free 10 billion web pages archived from 1996 to a few months ago Wayback Machine – search to look at old versions of web pages Wayback Machine Books on the web Million Book Project digitizing books and providing free access International Childrens Digital Library online children books Digital books Index links to more than 105,000 title records from more than 1800 commercial and non-commercial publishers, universities, and various private sites

30 Principles of Searching © Tefko Saracevic29 Language barriers on the Web English still the major language but declining, now slightly over 50% Multilingual retrieval search engines Euroseek searches in a number of languages All the Web results in 45 languages

31 Principles of Searching © Tefko Saracevic30 Web news; keeping up What is going on on the Web? Some major sources of news and evaluations: Free Pint newsletter, articles, links; nice & sometimes quirky Internet Resources Newsletter UK based; monthly newsletter for academics, students, engineers, scientists and social scientists ResearchBuzz daily updates; many aspects; Collection of items on search engines, online databases, and other information resources About.com Web Search tools, Web Search Forum

32 Principles of Searching © Tefko Saracevic31 keeping up … Information Today trade & professional monthly newspaper & web site; industry news; searcher columns; general analyses of trends Keeping up through blogosphere: Resource Shelf bloger about internet (and some other stuff) with archive; it has really good and really bad exchanges & threads New York Times blogrunnerNew York Times blogrunner - The annotated NYT blog tracking of NYT articles, topics, authors; thread into discussion of many other weblogs; includes net & web topics

33 Principles of Searching © Tefko Saracevic32 Finding links & listings – back to good old books with a new twist Number of books on web searching have also sites with links in the book, updates, news Extreme Searcher Randolph Hock Extreme Searcher update of a popular book; links by chapter topics The web libraryThe web library Nicholas G. Tomaiuolo spotlights free resources, links by chapter and new topics – done by a librarian The invisible webThe invisible web Chris Sherman & Gary Price original book on the topic, links organized by subject p.s. most, but not all, of the sites in this lecture can be found on those sites – and much, much more

34 Principles of Searching © Tefko Saracevic33 Evaluations, ratings Evaluating web sites: a prime responsibility of searchers & all information professionals Many sources evaluate web sites: The Scout Report – The Scout Report librarians BIBLE! Annotations. Comprehensive. Medical Library Association ten most useful sites for consumer health MLA user guide for finding & evaluating health information on the web Web 100 commercial, user ranking & evaluation of web sites Evaluating web pages UC Berkeley Evaluating web pages tutorial and guide

35 Principles of Searching © Tefko Saracevic34 Needed for Web searching Knowledge & competencies on variety of web sources & their organization search engines web search strategies search dynamics, feedback Keeping up & up & up Why? many reasons, such as: constant updates, changes, innovations many domain/subject specific fluidity very high

36 Principles of Searching © Tefko Saracevic35 Needed for web searching by professionals Knowledge of SOURCES in area of interest search engines not enough not too helpful in finding these other sources; structure hard to discern find & use specialized sources Evaluation of sources a key professional skill! application of standard criteria & web criteria : authority; accuracy; currency (timeliness); objectivity; coverage, persistence, usability

37 Principles of Searching © Tefko Saracevic36 Needed competencies … Knowledge of users & use Knowledge of searching Use of technology Adaptability, flexibility Integration with other resources Teaching others Constant learning & update again: keeping up, keeping up, keeping up and again: keeping up, keeping up, keeping up

38 Principles of Searching © Tefko Saracevic37 information WWW But now really: How to do it?

39 Principles of Searching © Tefko Saracevic38

40 Principles of Searching © Tefko Saracevic39

41 Principles of Searching © Tefko Saracevic40 Images from the invisible web

42 Principles of Searching © Tefko Saracevic41 images …

43 Principles of Searching © Tefko Saracevic42 images …

44 Principles of Searching © Tefko Saracevic43 and of course…

45 Principles of Searching © Tefko Saracevic44 P.S. a nice site Poem by Emily Dickenson: In a library Who will write a poem: In a digital library?

46 Principles of Searching © Tefko Saracevic45 P.S. a few weird sites… SelectSmart.com all kinds of quizzes for you James Dean official web site Deaducated Dead Librarians Society Livejournal blogs & authoring tools; and many pathetic entries

47 Principles of Searching © Tefko Saracevic46 Sources About.com Web Search Academic Info Digital Library All the Web Ask Jeeves! Assoc. for Computing Machinery Bibliothèque Nationale de France BUBL LINK CDNET Search.com CiteSeer CompletePlanet Deaducated Digital book index Digital librarian Diotima Dogpile Entrez PubMed Extreme Searcher Free Pint Gabriel Genealogy

48 Principles of Searching © Tefko Saracevic47 sources … Hermitage Information Please International Childrens Digital Library Internet Archive Internet Public Library, Michigan Internet Resources Newsletter. James Dean Kartoo KIRKE Leonardo da Vinci Museum Librarians Index to the Internet Live Journal LiveRef Mayo Clinic Medical Library Assoc. ten top sites Medical Library Assoc. user guide for health inf. Medscape

49 Principles of Searching © Tefko Saracevic48 sources … Million Book Project Museum of online museums. MuseumStuff NYT blogrunner NYT historical project OCLC Web Characterization Project Open Directory Project Perseus Digital Library Profusion Psychcrawler QuestionPoint ResearchBuzz. Resource Shelf Rutgers Libraries RxList Sch of East Eur & Slavonic Studies Search Engine Colossus Search Engine Guide Search Engine Showdown

50 Principles of Searching © Tefko Saracevic49 sources … Search Engine Watch Select Smart.com Snoopy Stanford Encyclopedia of Philosophy Surfwax Teoma The invisible Web The Scout Report. The Web Library Think Quest Turbo10 U California Berkeley U Mich Documents Center US State department Virtual Library Virtual Reference Desk Vivisimo Web 100 Webbrain WebMD Wikipedia


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