Web searching & the invisible Web

1. Web searching & the invisible Web Finding things that are hard to find tefkos@rutgers.edu; http://comminfo.rutgers.edu/~tefko/ Tefko Saracevic

2. Central ideas • Web has great many, even indispensable, information resource for searching • many of these are hard to find, forming the “invisible Web” • A variety of Web resources have to be accessed directly & not through common search engines – as explored here Tefko Saracevic

3. ToC • Invisible Web • Invisible Web searching • General sources • Domain sources • Reference sources and services • Digital libraries Tefko Saracevic

4. 1. Invisible Web Definition, characteristics, reasons Tefko Saracevic

5. A few definitions World wide web : Internet-connected files the very large set of linked documents and other files located on computers connected through the Internet and used to access, manipulate, and download data and programs Invisible Encarta hidden from view;not readily noticed or detected Invisible web (also deep Web, hidden Web as opposed to visible Web or surface Web) "Invisible Web" is the term used to describe all the information available on the World Wide Web that is not found by using general-purpose search engines. Tefko Saracevic

6. What is “Invisible web?” • Materials that general search engines cannot or will not include in their collection of web pages • You cannot find through general search engines • Contains a vast amount of information resources • much of it authoritative & higher quality than visible web • quality becomes a main issue • much of it specialized • a lot of it also fluid or streaming or real time • “You can’t step in the same river twice” • much of it free • Many times larger than the visible Web Tefko Saracevic

7. Size & characteristic of invisible web ( a lot from CUNY library) • Even the best search engines can access only about 16% of the available information on WWW • therefore 84% of the information is excluded = Invisible Web • put another way, the size of the Invisible Web is 500 times larger than the Surface Web • 95% of the Invisible Web is publicly accessible information • More than half of the Invisible Web resides in topic specific databases Thus, a lot of professional Web searching concentrates on the invisible Web. So will we in this lecture Tefko Saracevic

8. There is much more to the Web than or in other words… • “infobesity” • refers to the belief that searching Google for information provides a junk information diet • not concerned about the quality • coined by James Morris, the Dean of the School of Computer Science at Carnegie Mellon University Brophy & Biden, (2005) Tefko Saracevic

9. Why search engines do not cover all? • Size: web is huge, cannot cover all • Economics: associated costs are high • engines support themselves mostly by ads • some engines have rank per pay & crawl update per pay - providing paid listings first & mostly • Technical: still a challenge & limited capabilities • also some file formats hard to cover • Spam: eliminating bad also looses good • Restrictions: some site do not let in e.g. login required • Deep structure: some sites complex Tefko Saracevic

10. Not found … From: Characteristics of Invisible Web content Tefko Saracevic

11. Search engine coverage • Hard (impossible) to discern & compare coverage • Many national search engines • have own coverage, orientation, governance • Many topical or domain search engines • have own coverage geared to subject of interest • But: there are many comprehensive sources independent of search engines • some are search engines in specialized domains • others are compilations of evaluated web sources Tefko Saracevic

12. Search engines differ • Substantial differences among search engines on coverage • hard to impossible to discern • Substantial difference how they work • relatively easy to find out e.g. from • Search Engine Showdown • “The users’ guide to web searching” - run by a librarian, news links, ratings Tefko Saracevic

13. Be aware: search engines are not only about search • Yes, search is (still) their core, but they are in many other businesses built upon search & these affect what & how of searching for us • they are corporations, commercial entities • have to make money, mostly by ads & placements • but provide many other services • selling, licensing software • email, messenger • add-on utilities – desktop search functions, toolbars … • most of the additional stuff is provided free • but there is no such thing as free lunch - it is about how search engines can get us to continue to use their service Tefko Saracevic

14. 2. Invisible web searching A few pointers Tefko Saracevic

15. Invisible web searching:Basic approach User Resources Limit your search to appropriate resources & tools for the particular type of information you’re looking for know your sources know how to find appropriate sources shades of “Knowledge is of two kinds…” • The first step in determining the best approach for searching the invisible web is to have a clear idea of what you’re seeking • extensive user modeling Tefko Saracevic

16. Advanced searching on the Web – applies to searching of the invisible Web as well • Needs to be adapted to differences • coverage not specified; vastly different from one source, engine to another • no controlled vocabulary • output ranked by unknown methods & criteria for “relevance” • building blocks may be indicated by “similar pages” or “more from this site” or some such • some provide clusters to narrow searches • features, capabilities, specifics differ Tefko Saracevic

17. Specialized sources -particularly for the invisible web • Large scholarly search engines & directories • Domain sources, databases • Reference sources • Libraries as web sources • Virtual libraries Tefko Saracevic

18. A few tips for Web searching, including the invisible kind • Advanced web searcUniv. of California, Berkeley • Four NETS for better searching Bernie Dodge • Web search tutorial Searchenginez • Finding information: search engines Phil Bradley • Google GuideNancy Blachman Tefko Saracevic

19. 3. General sources A selection of a few (of great many) sources for invisible web Tefko Saracevic

20. Characteristics • Many oriented toward scholarly, research & professional, technical & related information • include sources mostly not covered by general search engines • majority of these are trustworthy • quality much higher, some carefully selected, some edited • origins vary widely • from commercial to voluntary to government sponsored • Popular in many disciplines Tefko Saracevic

21. Large scholarly search engines & directories - sample • Infomine - a comprehensive virtual library and reference tool for academic and scholarly Internet resources, including Web sites, databases • covers a wide range of scholarly resources by fields • Scirus–“it allows researchers to search for not only journal content but also scientists' homepages, courseware, pre-print server material, patents and institutional repository and website information. “ • by Elsevier, run in conjunction with Scopus and Science Direct, but this one free • Google Scholar“Stand on the shoulders of giants” (but Newton and John of Salisbury said it better) • searches for scholarly articles & resources, but sources not disclosed (no idea on what it covers ) Tefko Saracevic

22. Large edited sites 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 Tefko Saracevic

23. Science, scholarship engines, not free – a sample • In addition to freely accessible engines many provide search free but access to full text paid • by subscription or per item • RUL provides access to these & many more • General ScienceDirect Elsevier: “world's largest electronic collection of science, technology and medicine full text and bibliographic information”[available at RUL] • In a specific domain ACM Portal Asoc. for Computing Machinery:access to ACM Digital Library & Guide to Computing [available at RUL] Tefko Saracevic

24. 4. Domain sources Hardly a field without it Tefko Saracevic

25. Domain engines • Cover specific subjects & topics • from sciences, arts, humanities, to various media & interests – you name it • Important tool for subject searches • particularly for subject specialist • valued by professional searchers • Selection mostly hand-picked rather than by crawlers, following inclusion criteria • often not readily discernable • but content more trustworthy • Usually well organized Tefko Saracevic

26. in health & related fields … • PubMed– Nat Library of Medicine • biomedical literature from MEDLINE & health journals • Psychcrawler - Amer. Psychological Association • web index for psychology • WebMDHealth • news, medical information • Rxlist • The Internet Drug Index • Mayo Clinic HealthOasis • health advice Kidshealth sites for parents, kids, teen Tefko Saracevic

27. in science … Ocean PlanetNASA presentation of earth & its vast oceans ArXivCornell U, National Science Foundation e-print service in the fields of physics, mathematics, computer science, and quantitative biology large, non-reviewed contribution by authors, comments later Athena Earth Sciences Resources not a search engine but a large well organized directory Tefko Saracevic

28. in education … Intute “Intute is a free online service providing you with a database of hand selected Web resources for education and research.” Think Quest– Oracle Education Foundation education resources, programs; web sites created by students Resource Discovery Network– UK “UK's free national gateway to Internet resources for the learning, teaching and research community” Tefko Saracevic

29. in images, movies, video … Internet Movie Database • treasure trove of movies Picsearch picture searching Blinkx claims to be word largest search engine for videos; it has indexed over 32 million hours worth of video footage, made searchable by automatically transcribing the speech content. 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. Tefko Saracevic

30. in humanities … Shakespeare & Internet Search Tools & Resources • great fun to navigate • KIRKE -Katalog der Internetressourcen für die Klassische Philologie aus Erlangen • German; a variety of resources for classics • Perseus Digital LibraryTufts University • 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 • includes country resources, e.g. Croatia Diotima Materials for study of women and gender in the Ancient World Tefko Saracevic

31. in music … Musipedia Not everything is text. This is “a searchable, editable, and expandable collection of tunes, melodies, and musical themes.” Great fun! All Music Guide • resource about musicians, albums, and songs Tefko Saracevic

32. governments … • U Mich Document Center • official documents from all over the world • US government official web portal“Whatever you want or need from the U.S. government” • US State Department • about the U.S & other countries FirstGov the US government official web portal Tefko Saracevic

33. Evaluations, ratings • Evaluating web sites: a prime responsibility of searchers & all information professionals • Many sources evaluate web sites: • 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 pagesUC Berkeley tutorial and guide Tefko Saracevic

34. also a domain resource And, of course … Snoopy The Official Peanuts Website Tefko Saracevic

35. 5. References a few sources & services Tefko Saracevic

36. Reference trends Transactions Tools Most, if not even all reference tools migrated to digital general & in many domains Many free online access Others licensed to libraries End users oriented but still important source for searchers • Live reference transactions in libraries falling off dramatically • But new reference modes emerging • chat, ask a librarian • cooperative reference among group of libraries • Commercial reference growing strong Tefko Saracevic

37. Reference tools – open access Wikipedia web encyclopedia in many languages; user generated; very popular; but uneven & entries at times manipulated Stanford Encyclopedia of Philosophy a comprehensive encyclopedia; authoritative - maintained and kept up to date by experts in the field Bartleby.com“Great books online” dozen of reference books; Harvard classics; English usage; and more. Amazing, invaluable collection Tefko Saracevic

38. At RUL 100s of digital reference sources in all domains Tefko Saracevic

39. Reference services • Reference services - several models • Commercial – relatively new & successful • Ask(originally known as Ask Jeeves) • most popular, commercial • Information Please • almanac type questions RefDesk access to a number of reference tools • ChaCha - new service • direct answers to questions routed to any device. “ChaCha’s advanced technology instantly routes it to the most knowledgeable person on that topic in our Guide community” – to any device Tefko Saracevic

40. Cooperative reference & real time reference • Digital reference - new service area for libraries • QuestionPoint L of Congress & OCLC • project for a global 24/7 reference network • Virtual Reference Desk– L of Congress • large compilation of web reference sites • LiveRef - maintained at Iowa State U • a registry of real time digital reference services Tefko Saracevic

41. 5. Libraries & other institutions as web sources Digital libraries, virtual libraries, museums, good old books Tefko Saracevic

42. Libraries as web sources • Academic, national libraries providing open collections & services; models vary • Rutgers libraries- big long term effort • University of California, Berkeley • a most elaborate effort together with Sun Corporation LibWebby Webjunction, formerly at U California, Berkeley “lists currently over 7900 Web pages from libraries in 146 countries” • Bibliothèque Nationale de France • includes virtual exhibitions, among others Tefko Saracevic

43. Virtual libraries • Libraries “living” only on the Web • Virtual Library– • Switzerland, US, UK & other countries – ‘oldest virtual library on the Web’ • Internet Public LibraryDrexel formerly at U of Michigan • “the first public library of and for the Internet community” • Librarians Index of the InternetDrexel • very popular and comprehensive - directory Digital librarianmaintained by Margaret Vail Anderson, a librarian in Cortland, New York “a librarian's choice of the best of the Web “ – large directory Tefko Saracevic

44. Museums, societies… • Growing number of resources in museums & variety of societies – rich resource for searching • Museum of online museums • a delight 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! Tefko Saracevic

45. Archiving, books on the web • Internet Archive– a large undertaking • 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 Tefko Saracevic

46. Digital books on the Weba sample of large projects • Books on the web – searchable Million Book Project digitizing books and providing free access International Children’s Digital Library online children books Digital books Index “"Meta-index" for most major eBook sites, along with thousands of smaller specialized sites. ” Google Book Search large digitization effort; many large libraries cooperate; agreement reached with publishers; connected with Worldcat Tefko Saracevic

47. 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 Tefko Saracevic

48. 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 Tefko Saracevic

49. 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 Tefko Saracevic

50. 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 Tefko Saracevic