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Instructor: Shayna Keces Finding information on the internet Basic Internet Search Techniques August 2002.

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Presentation on theme: "Instructor: Shayna Keces Finding information on the internet Basic Internet Search Techniques August 2002."— Presentation transcript:

1 Instructor: Shayna Keces Finding information on the internet Basic Internet Search Techniques August 2002

2 Agenda Size of Internet Search strategies Types of search engines Choosing a search engine Interpretation of search results

3 Size of Internet/World Wide Web July 2000 2.1 billion web pages, est. 4 billion pages by early 2001 (Some place much higher if count invisible or deep web) Size of search engine databases Google 2+ billion Fast (alltheweb) 2.1 billion AltaVista 1.1 billion Yahoo 2 million catalogued (Google for not catalogued)

4 Search strategies Do nots use search button use a string of keywords without specifying Boolean properties use upper case (capitals) unless part of strategy use NOT or - unless absolutely sure is necessary elimination of unanticipated pages format is non standardized

5 Search Strategies Do Consider what type of resource will best answer your question and search for that resource (eg. dictionary or certain type of web page) think of a list of keywords that will narrow or broaden your search keeping in mind that with the internet, narrowing your search is usually better Stick to small list of search engines and learn the search syntax for the search engine you’re using

6 What is a search engine? Website that will help you find another website with information you need Will not search databases or in most cases documents called PDF documents (Google major exception) Must use keywords to help you find information

7 Types of search engines Keyword or robot based (builds a database) Directory based (categories indexed by people rather than computer) Annotated directory-based search engines Metaindexes (can combine searches or allow you to search a variety of engines individually) Specialized search engines

8 Keyword or robot based Search Engines Large database of webpages No human involvement and no quality control Can submit website or will find some on own Searches full text to certain level Google (www.google.com)www.google.com Alta Vista (www.altavista.com)www.altavista.com Hotbot (www.hotbot.com)www.hotbot.com Fast (www.alltheweb.com)www.alltheweb.com

9 Google (www.google.com or www.google.ca )www.google.com www.google.ca Presently one of largest database (over 2 billion sites, but includes linked sites not in database) Very sophisticated placement of results particularly good for popular sites, company sites Advanced search can limit search to title of page or to URL implied AND + for stopwords

10 Google (cont.) If you want or needs to be expressed in caps not case sensitive no stemming description shows keywords in context cached pages Searches some formats not found in other search engines (eg. Adobe acrobat and postscript files, Word, Excel and PowerPoint documents and rich text files)

11 AltaVista (www.altavista.com)www.altavista.com One of the larger search engines Particularly good for finding less popular sites Must use pluses and minuses since sometimes has implied and and sometimes or Case sensitive, Caps will only retrieve caps Stemming with * at end of or in middle of words Search within these results

12 AltaVista (cont.) Sophisticated search of elements, url, text, images, image and like http://doc.altavista.com/help/search/search_w eb_elements.html http://doc.altavista.com/help/search/search_w eb_elements.html Has advanced search capability but instructions very different from regular search Prisma new service that suggests often used keywords

13 Directory-based Search Engines Indexed by individuals so subject searches will be more accurate Smaller database than Robot engines Used mainly for finding a good site on a general topic Yahoo (www.yahoo.com or ca.yahoo.com)www.yahoo.com ca.yahoo.com About (about.com or home.about.com/aboutcanada)about.com home.about.com/aboutcanada Looksmart (www.looksmart.com)www.looksmart.com

14 Yahoo (ca.yahoo.com)ca.yahoo.com Most popular of directory based search engines Many different versions (international have same pages as others but local options are supplied first) Uses Google as search engine Can search by categories and move up and down the category structure by clicking on category and looking at hierarchy

15 About (about.com or home.about.com/aboutcanadaabout.com home.about.com/aboutcanada Another popular directory-based search engine Volunteer guides responsible for finding good websites on appropriate subjects Some guides exist on all version of About but geographic versions have items specific to country

16 Annotated directory-based search engines Because annotated, database is even smaller than Directory-based engine Quality of webpages is better Webpages often rated Librarian’s Index to the Internet (lii.org)lii.org Argus Clearinghouse (www.clearinghouse.net)www.clearinghouse.net

17 Argus Clearinghouse (www.clearinghouse.net)www.clearinghouse.net Topical list of fairly scholarly guides submitted to Argus on a variety of subjects. Can have more than one guide or page on the same subject. Not all are accepted and all are objectively rated by Argus staff and the detailed rating in available. Because Argus does not solicit webpages, coverage is uneven Date of rating is also provided

18 Metaindexes One site searches more than one search engine Results can be separated or combined Sometimes a problem in interpreting question for all search engines Used if not sure which search engine will give you best results and/or obscure topics

19 Metaindexes examples Dogpile (www.dogpile.com)www.dogpile.com Metacrawler (www.metacrawler.com/index.html)www.metacrawler.com/index.html Surfwax (www.surfwax.com)www.surfwax.com All4one Search machine (www.all4one.com)www.all4one.com

20 Specialized Search Engines Geographic based (www.altavistacanada.com, www.google.ca www.surfottawa.com)www.altavistacanada.comwww.google.ca www.surfottawa.com Phone directories (canada411.sympatico.ca/, home.infospace.com/)canada411.sympatico.ca home.infospace.com/ Newsgroup searching (groups.google.com)groups.google.com Women’s information (wwwomen.com)wwwomen.com

21 Specialized sites Ottawa Public Library (www.library.ottawa.on.ca)www.library.ottawa.on.ca Reference tools (see library reference sites, eg. lii.org, www.ipl.org/ref)lii.orgwww.ipl.org/ref Encyclopedias (www.britannica.com, Columbia encyclopedia www.bartleby.com/65/www.britannica.com www.bartleby.com/65/ Canadian information (vrl.tpl.toronto.on.ca/, Canadian information by subject www.nlc- bnc.ca/caninfo/ecaninfo.htm, Canadian encyclopedia online, www.thecanadianencyclopedia.com/vrl.tpl.toronto.on.ca/www.nlc- bnc.ca/caninfo/ecaninfo.htm www.thecanadianencyclopedia.com/

22 Some hints on selecting search strategies For any page on general topic you need an introduction try Directory-based search engine. If do not need specific quality can use address bar search For webpage of major company or organization try Google or Alta Vista if more obscure For a specific webpage that would not necessarily be popular try Alta Vista.

23 Some hints on selecting search strategies cont. For health topics try health website engine like www.medbroadcast.com or health links on OPL webpage.www.medbroadcast.com For very obscure topic topic try Google or Alta Vista or one of metaindexes For Canadian information, use a Canadian search engine For items in databases try to find the correct host or search special site for Invisible web sites (eg. http://www.invisible-web.net/)http://www.invisible-web.net/

24 Interpretation of search results Look at results and reformat search using things like searching within results and adding new keywords Analytically choose which sites to look at in result list Anatomy of URL domain Name of server Name of organization Type of organization (eg., com, edu, gov, net, org, geographic name like ca) Folder and page name

25 Interpretation of search results (cont.) Do not look through pages and pages of results. If first three pages are not promising redo search

26 Some useful tutorials for searching See “Learning to search” section of Collection of special search engines www.leidenuniv.nl/ub/biv/specials.htm Web searching tips www.searchenginewatch.com/facts/index.htm l www.searchenginewatch.com/facts/index.htm l Net tutor (gateway.lib.ohio- state.edu/tutor/les5/)gateway.lib.ohio- state.edu/tutor/les5/ Check links under Internet, General in OPL adult links (www.library.ottawa.on.ca)www.library.ottawa.on.ca

27 To Find more info on Search engines Searchenginewatch (www.searchenginewatch.com)www.searchenginewatch.com Searchengineshowdown (www.searchengineshowdown.com)www.searchengineshowdown.com


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