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James Tam Computer Searches Concepts covered What is a search engine and how do they work? General search tips The Big Six search engines Other search.

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Presentation on theme: "James Tam Computer Searches Concepts covered What is a search engine and how do they work? General search tips The Big Six search engines Other search."— Presentation transcript:

1 James Tam Computer Searches Concepts covered What is a search engine and how do they work? General search tips The Big Six search engines Other search tools Much of these lecture notes were based on Search Engines for the World Wide Web by Alfred and Emily

2 James Tam Looking for Information? Start with the Internet World wide web Newsgroups Archived mailing lists There are potential problems

3 James Tam Search Engines What is a search engine How do they work Search engines may employ spiders The Internet

4 James Tam Search Engines (Continued) Search engines may search human-created databases

5 James Tam Making Your Web Site More Noticeable Add relevant keywords (Spiders) Search engine submission (“suggesting your site” to Humans)

6 James Tam Keywords: The Secret To Effective Searches Use keywords that are unique as possible Run the search using a number of variations Search only titles Determine if the search engine is case sensitive When searching for proper names, capitalize the first letters Check your spelling Re-run previous results

7 James Tam Types Of Searches Plain English AND OR NOT Near Searches

8 James Tam Plain English Searches (Natural Language Searches) Easy to formulate the query but may result in too many hits

9 James Tam Plain English Searches (Continued) Supported by almost all of the Big Six AskJeeves (www.ask.com)

10 James Tam AND Searches Telling the search engine that it must include multiple keywords Precede each keyword with a plus sign "+“ or “AND” Some search engines use AND as the default, others do not

11 James Tam OR Searches Provides broader search results Tells the search engine to include web pages that include at least one keyword out of a list of many (2+)

12 James Tam NOT Searches Precede the excluded keyword with a minus sign "-“ or “NOT”

13 James Tam NEAR Searches Tell the search Engine to show web pages where keywords appear near each other in the document (within 10 words)

14 James Tam Using Wildcards "*" Used to look for variations on particular words Some search engines allow the wildcard to be placed at the beginning, middle or end of a keyword Rules of thumb on the use of wildcards Use them to find spelling variations Use a minimum of three characters before the wildcard 1 This will vary depending upon the particular search engine.

15 James Tam Stopwords Ignored by search engines because they are too common or are reserved for some special purpose Common words Reserved words The search engine can be forced to include the stopwords Use quotes Use a plus sign

16 James Tam Topic Directories

17 James Tam Searching within a web page

18 James Tam Opening A New Browser

19 James Tam The Big Six AltaVista (www.altavista.com)www.altavista.com Google (www.google.com)www.google.com HotBot (www.hotbot.com)www.hotbot.com Lycos (www.lycos.com)www.lycos.com Northern Light (www.northernlight.com)www.northernlight.com Yahoo (www.yahoo.com)www.yahoo.com

20 James Tam Comparing The Big Six Search Engine Number of Web pages in database Percentage of web in database 1 Google1.2 billion57% Yahoo (powered by Google) 1.2 billion57% Lycos575 million27% HotBot500 million24% AltaVista350 million17% Northern Light 330 million16% 1 Based upon figures from January 2001 and an estimate of 2 billion web pages in existence from www.searchenginewatch.com Self-reported sizes But size isn't everything!

21 James Tam AltaVista Types of searches Logical OR Date Field Geographic Wildcards Language Case sensitive Proximity Weighted Babel Fish Obscure facts and figures Dead links

22 James Tam AltaVista (Continued) Ranking of search results Appearance in the title Appearance near the beginning of the document Links to related content

23 James Tam Google Types of searches Logical OR Language Domain Type of file Date Not case sensitive No wildcards Specifies stopwords Big! Caches web pages I feel lucky feature

24 James Tam Google (Continued) Ranking of search results By the number of links

25 James Tam HotBot Types of searches Logical OR Case sensitive Wildcard searches Language Date Domain Geographic region Link searches Type of file Must contain, should contain, should not contain Graphical control of searches

26 James Tam HotBot (Continued) Ranking of search results Having the keyword(s) in the title Number of occurrences of the keyword

27 James Tam Lycos Types of searches Logical AND Multi-media searches Must include/should include, exclude Link searches No Stop words Not case sensitive No searches by date No searches by wildcard Kid's search site www.lycoszone.com

28 James Tam Lycos (Continued) Ranking of search results "Popularity" of site Occurrences of keyword

29 James Tam Northern Light Types of searches Logical AND Special case sensitive search Wildcard Singular and plural Stop words WWW and a special database Free search alerts Customized search folders

30 James Tam Northern Light (Continued) Ranking of search results By the number of links Keyword frequency Date of the document Keyword appearing in title

31 James Tam Yahoo Searches Logical OR Date added Wildcards Not case-sensitive Searches Yahoo directories and Google database Extensive classification

32 James Tam Yahoo (Continued) Ranking of search results Results in Yahoo directory comes before Google results Ranking in Yahoo directory determined by: -The number of key words matched -Exact word matches -Location of the word in the web page

33 James Tam Summary of The Big Six and What They Do Best 1 AltaVista Obscure facts and figures Babel fish Google Big! Often produces relevant search results Caches web pages HotBot Multimedia Ease of use 1 From Search Engines for the World Wide Web by Alfred and Emily

34 James Tam Summary of The Big Six and What They Do Best (Continued) Lycos Multimedia Kid's zone Northern Light Search on the web and special data bases Yahoo The most extensive web directory

35 James Tam Metasearch engines Search on multiple search engines automatically Examples www.metacrawler.com www.dogpile.com www.profusion.com www.search.com www.mamma.com Drawbacks Searches occur in the simplest form Timeouts Number of results returned

36 James Tam Other (Task-Specific) Search Tools Products Amazon: www.amazon.comwww.amazon.com CDNOW: www.cdnow.comwww.cdnow.com Consumer World: www.consumerworld.orgwww.consumerworld.org CNET Shareware.com: www.shareware.comwww.shareware.com ZDNet: www.zdnet.comwww.zdnet.com Health CDC: www.cdc.govwww.cdc.gov

37 James Tam Other (Task-Specific) Search Tools (Continued) Food CuisineNet Menus Online: www.cuisinenet.comwww.cuisinenet.com Epicurious Food: www.epicurious.comwww.epicurious.com Martha Stewart: www.marthastewart.comwww.marthastewart.com Miscellaneous Expedia: www.expedia.comwww.expedia.com Internet Movie Database: www.imdb.comwww.imdb.com Monster: www.monster.cawww.monster.ca Workopolis: www.workopolis.comwww.workopolis.com

38 James Tam Summary What is a search engine? How do search engines gather information for their databases? Types of Searches By keyword Logical Plain English Wildcards Stopwords and searches. Browsing topic directories. What are the Big Six search engines? Metasearch engines. Task-specific search tools


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