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Title: Searching the Web


1
Searching the Web
Tutorial 3
  • Using Search Engines and
  • Directories Effectively

2
Objectives
  • Determine whether a research question is specific
    or exploratory.
  • Learn how to formulate an effective Web search
    strategy to answer research questions.
  • Learn how to use Web search engines, Web
    directories, and Web metasearch engines
    effectively.

3
Objectives
  • Use Boolean logic and filtering techniques to
    improve your Web searches.
  • Use advanced search options in Web search
    engines.
  • Assess the validity and quality of Web research
    resources.
  • Learn about the future of Web search tools.

4
Types of Search Questions
  • Specific question a question that you can phrase
    easily and one for which you will recognize the
    answer when you find it.
  • Exploratory question an open-ended question that
    can be harder to phrase it is also difficult to
    determine when you find a good answer.

5
Specific Question
New Perspectives on The Internet, Sixth
EditionComprehensive Tutorial 3
5
6
Exploratory Question
New Perspectives on The Internet, Sixth
EditionComprehensive Tutorial 3
6
7
Web Search Process
New Perspectives on The Internet, Sixth
EditionComprehensive Tutorial 3
7
8
Web Search Strategy
  • You may need to reformulate, or more clearly
    state, your question.
  • Try to think of synonyms for each word.
  • Identify unique phrases that relate to your topic
    or question.

9
Using Search Engines
  • Four Broad Categories Of Search Tools
  • Search engines
  • Directories
  • Metasearch engines
  • Other Web resources such as Web bibliographies

10
Understanding Search Engines
  • Search engine a Web site (or part of a Web site)
    that finds other Web pages that match a word or
    phrase you enter.
  • Search expression or query the word or phrase
    you enter in a search engine.
  • A search expression might also include
    instructions that tell the search engine how to
    search.
  • A search engine does not search the Web to find a
    match it searches only its own database of
    information about Web pages that it has
    collected, indexed, and stored.

11
Understanding Search Engines
  • Hit a Web page indexed in the search engines
    database that contains text that matches your
    search expression.
  • Most search engines report the number of hits
    they find.
  • Results pages a list of Web pages in a search
    engine that contain hyperlinks to the Web pages
    that contain text that matches your search
    expression.

12
Understanding Search Engines
  • Web robot (bot or spider) a program that
    automatically searches the Web to find new Web
    sites and update information about old Web sites
    that already are in the database.
  • Most search engines allow Web page creators to
    submit the URLs of their pages to search engine
    databases.
  • Search engine operators often sell advertising
    space on the search engine Web page and on the
    results pages.

13
Understanding Search Engines
  • Sponsored links paid placement links on results
    pages.
  • Banner ad a sponsored link that appears in a box
    on the page (usually at the top, but sometimes
    along the side or bottom of the page).
  • Revenue from sponsored links and banner ads is
    used to generate profit after covering the costs
    of maintaining the computer hardware and software
    required to search the Web and to create and
    search the database.

14
Understanding Search Engines
Google search results for the search term car
New Perspectives on The Internet, Sixth
EditionComprehensive Tutorial 3
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15
Using More Than One Search Engine
  • Each search engine includes different Web pages
    in its database.
  • Each search engines use different rules to
    evaluate search expressions.
  • The best way to determine how a specific search
    engine interprets search expressions is to read
    the Help pages on the search engine Web site.
  • Search engines change the way they interpret
    search expressions from time to time, so you
    should read the Help pages regularly.

16
Understanding Search Engine Databases
  • Search engine databases store different
    collections of information about the pages that
    exist on the Web at any given time.
  • Each search engine database indexes the
    information it has collected from the Web
    differently.
  • Search engine robots may collect information from
    a Web pages title, description, keywords, HTML
    tags, or read a certain number of words from each
    Web page.

17
Understanding Search Engine Databases
META tags in a Web page
  • Meta tag HTML code that a Web page creator
    places in the page header for the specific
    purpose of informing Web robots about the content
    of the page.
  • Current Developments in
    Electronic Commerce
  • and reports about electronic commerce
    developments."
  • commerce, electronic data interchange, value
    added reseller, EDI, VAR, secure socket layer,
    business on the internet"

18
Understanding Search Engine Databases
  • Full text indexing when search engines store the
    entire content of every Web page they index.
  • Stop words common words, such as and, the, it,
    and by, that many search engines omit from their
    databases.
  • Many search engines include information about
    their search engines, robots, and databases on
    their Help or About pages.

19
Search Engine Features
  • Page ranking a way of grading Web pages by the
    number of other Web pages that link to them.
  • URLs of Web pages with high rankings are
    presented first on search results pages.
  • Natural language query interface allows users to
    enter a question exactly as they would ask a
    person that question.
  • Parsing the procedure of converting a natural
    language question into a search expression.
  • Stemming the use of the root form of a word to
    find results containing the root word and its
    variations, which are created by adding standard
    endings to the root word.

20
Search Engine Features
Natural language query on Ask.com
New Perspectives on The Internet, Sixth
EditionComprehensive Tutorial 3
20
21
Using Directories and HybridSearch Engine
Directories
  • Web directory a listing of hyperlinks to Web
    pages that is organized into hierarchical
    categories.
  • The difference between a search engine and a Web
    directory is that people select the Web pages to
    include in a Web directory.
  • Many directories allow a Web page to be indexed
    in several different categories.
  • The main weakness of a Web directory is that you
    must know which category is likely to yield the
    information you desire.
  • Yahoo! is one of the oldest and most respected
    directories on the Web.

22
Using Directories and HybridSearch Engine
Directories
Yahoo! Web directory
New Perspectives on The Internet, Sixth
EditionComprehensive Tutorial 3
22
23
Using Directories and HybridSearch Engine
Directories
  • Hybrid search engine directory the combination
    of search engine and directory.
  • Using a hybrid search engine directory can help
    you identify which category in the directory is
    likely to contain the information you need.
  • After you enter a category, the search engine is
    useful for narrowing a search even further. You
    can enter a search expression and limit the
    search to that category.

24
Using Metasearch Engines
  • Metasearch engine
  • a tool that lets you search several engines at
    the same.
  • does not have its own database of Web information
  • accepts a search expression and transmits it to
    several search engines, which run the search
    expression against their databases and then
    return results to the metasearch engine, which
    then reports consolidated results from all of the
    search engines it queried
  • Mamma.com was one of the first metasearch engines
    on the Web.

25
Using Metasearch Engines
Mamma.com was one of the first metasearch
engines on the Web.
New Perspectives on The Internet, Sixth
EditionComprehensive Tutorial 3
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26
Using Metasearch Engines
  • In the Kartoo metasearch engine, hits are shown
    as images each image is clustered around words
    that appear in the results pages.
  • When the pointer is moved over a word, the links
    appear as lines between the word and the images.
  • To refine a search, click a word to add it to the
    search expression.

New Perspectives on The Internet, Sixth
EditionComprehensive Tutorial 3
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27
Using Other Web Resources
  • Web bibliographies Web search tools that are
    similar to bibliographies in that they contain
    lists of hyperlinks to Web pages, but instead
    contain list of links to Web pages.
  • Many of these resources include summaries or
    reviews of Web pages.
  • Also called
  • Resource lists
  • Subject guides
  • Clearinghouses
  • Virtual libraries

28
Using Other Web Resources
  • Web bibliographies are sometimes confusingly
    called Web directories.
  • are usually more focused on specific subjects
    than Web directories
  • usually do not include a tool for searching
    within their categories.
  • Web bibliographies can be very useful when you
    want to obtain a broad overview or a basic
    understanding of a complex subject area.
  • Some Web bibliographies are general references,
    but most are more focused.
  • Many Web bibliographies are created by librarians
    at university and public libraries.

29
Boolean Logic andFiltering Techniques
  • The most important factor in obtaining good
    results in a Web search is careful selection of
    the search terms you use.
  • You can usually choose one or two words that will
    work well when the object of your search is
    straightforward.
  • More complex search questions require more
    complex queries, which you can use along with
    Boolean logic, search expression operators, or
    filtering techniques, to broaden or narrow your
    search expression.

30
Boolean Operators
  • Boolean algebra was developed by George Boole, a
    nineteenth century British mathematician.
  • Boolean operators, or logical operators, specify
    the logical relationship between the elements
    they join.
  • Three basic Boolean operatorsAND, OR, and
    NOTare recognized by most search engines.
  • You can use these operators in many search
    engines by including them with search terms.

31
Boolean Operators
32
Other Search Expression Operators
  • A precedence operator, also called an inclusion
    operator or a grouping operator, clarifies the
    grouping within a complex expression and is
    usually indicated by the parentheses symbols.
  • A location operator, or proximity operator, lets
    you search for terms that appear close to each
    other in the text of a Web page. The most common
    location operator offered in Web search engines
    is the NEAR operator.

33
Wildcard Characters
  • Wildcard character
  • allows you to omit part of a search term.
  • most search engines support some use of a
    wildcard character in their search expressions.
  • many search engines recognize the asterisk () as
    the wildcard character.

34
Search Filters
  • Search filter
  • eliminates Web pages from a search.
  • the filter criteria can include such Web page
    attributes as language, data, domain, host, or
    page component.
  • many search engines allow you to restrict your
    search by using them.

35
Complex Searches
  • Most search engines implement many of the
    operators and filtering techniques you have
    learned about.
  • Some search engines provide separate advanced
    search pages for these techniques.
  • Some search engines allow you to use advanced
    techniques such as Boolean operators on their
    simple search pages.

36
Using AltaVistaAdvanced Search
  • Open the AltaVista search engine in your Web
    browser.
  • Select the Advanced Search option.
  • Formulate and enter a suitable search expression.
  • Click the Find button.
  • Evaluate the results and, if necessary, revise
    your search expression.

37
Using AltaVista Advanced Search
Complex search in AltaVista for the search
expression Germany AND (trade or treat) AND
agricult
New Perspectives on The Internet, Sixth
EditionComprehensive Tutorial 3
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38
Filtered Search in Ask Jeeves
  • Open the Ask Jeeves search engine page in your
    Web browser.
  • Select the Advanced Options link.
  • Formulate and enter a suitable search expression.
  • Set any filters you want to use for the search.
  • Click the Ask button.
  • Evaluate the results and, if necessary, revise
    your search expression.

39
Filtered Search in Ask Jeeves
Advanced search page in Ask Jeeves for the search
expression rice harvest Filtered to search only
for pages from Southeast Asia and modified in the
last six months
New Perspectives on The Internet, Sixth
EditionComprehensive Tutorial 3
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40
Filtered Search in Google
  • Open the Google search engine page in your Web
    browser.
  • Click the Advanced Search link.
  • Formulate and enter suitable search expression
    elements.
  • Formulate and set appropriate search filters.
  • Click the Google Search button.
  • Evaluate the results and, if necessary, revise
    your search expression.

41
Filtered Search in Google
Advanced search page in Google for the search
expression Finland School of Economics Filtered
to search only for pages in English and from the
TLD .fi.
New Perspectives on The Internet, Sixth
EditionComprehensive Tutorial 3
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42
Search Engines withClustering Features
  • Vivísimo is a search engine that uses advanced
    technology to group its results into clusters.
  • The clustering of results provides a filtering
    effect.
  • The filtering is done automatically by the search
    engine after it runs the search.

43
Obtaining Clustered Search Results Using Vivísimo
  • Open the Vivísimo search engine page in your
    browser.
  • Formulate and enter a suitable search expression.
  • Click the Search button.
  • Evaluate the results and, if necessary, revise
    your search expression.

44
Obtaining Clustered Search Results Using Vivísimo
New Perspectives on The Internet, Sixth
EditionComprehensive Tutorial 3
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45
Future of Web Search Tools
  • Most search engines cannot search the deep Web
    (hidden Web or invisible Web).
  • static Web page an HTML file that exists on a
    Web server
  • dynamic Web page a Web page generated as a
    result of a users query
  • dynamic Web pages are not stored permanently on a
    Web server and cannot be found by bots
  • much of the content on dynamic Web pages is
    accessible only by logged in users
  • Work on natural language interfaces continues as
    search engine sites strive to make the job of
    searching even easier for users.

46
Using People to EnhanceWeb Directories
  • About.com hires people with expertise in specific
    subject areas to create and manage their Web
    directory entries in those areas.
  • The Open Directory Project uses the services of
    more than 40,000 volunteer editors who maintain
    listings in their individual areas of interest.
  • offers the information in its Web directory to
    other Web directories and search engines at no
    charge
  • many major Web directories, search engines, and
    metasearch engines regularly download and store
    the Projects information in their databases.

47
Evaluating the Validity and Quality of Web
Research Resources
  • Information on the Web is seldom subjected to the
    review and editing processes that have become a
    standard practice in print publishing.
  • The risks of obtaining and relying on inaccurate
    or unreliable information can be significant.
  • Reduce your risk by carefully evaluating the
    quality of any Web resource on which you plan to
    rely for information related to an important
    judgment or decision.
  • Evaluate on the Web pages authorship, content,
    and appearance.

48
Author Identity and Objectivity
  • Web pages should identify the author and present
    the authors background information and
    credentials.
  • Check secondary sources for corroborating
    information.
  • Author contact information should be provided.
  • Examine the domain identifier in the URL.
  • Consider whether the qualifications presented by
    the author pertain to the material that appears
    on the Web site.
  • Information about the authors affiliations
    should be provided.

49
Content
  • Determine timeliness of the content by checking
    the publication date.
  • Read the content critically and evaluate whether
    the included topics are relevant to the research
    question at hand.
  • Determine whether important topics or
    considerations were omitted.
  • Assess the depth of treatment the author gives to
    subject.

50
Form and Appearance
  • Many pages that contain low-quality or incorrect
    information are poorly designed and not well
    edited.
  • A Web page that contains spelling errors might
    indicate a low-quality resource.
  • Loud colors, graphics that serve no purpose, and
    flashing text are all Web page design elements
    that often suggest low-quality resource.

51
Evaluating the Quality of a Web Site
  • Open the Web page in your Web browser.
  • Identify the author, if possible. If you can
    identify the author, evaluate his or her
    credentials and objectivity.
  • Examine the content of the Web site.
  • Evaluate the sites form and appearance.
  • Draw a conclusion about the sites overall
    quality.

52
Summary
  • You learned how to formulate specific and
    exploratory research questions.
  • You learned how to use a structured Web search
    process to find information on the Web.
  • You learned how to develop search expressions and
    used them in search engines, Web directories, and
    metasearch engines.

53
Summary
  • You learned what Boolean operators, precedence
    operators, and location operators are and how
    they work in several major search engines.
  • You learned how to use wildcards in search
    expressions.
  • You learned how to use several types of filtering
    techniques to narrow your search results.

54
Summary
  • You learned how to evaluate the validity and
    reliability of a Web page by using information
    about author identity and objectivity.
  • You learned how to evaluate the validity and
    reliability of a Web page by evaluating content,
    form and appearance.
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