1 SEARCHING FOR TRUTH Locating Information on the WWW chapter 5

2 Characteristics of Directories Topical lists of Internet Resources arranged in a hierarchical way differ from search engines: humans maintain directories and search engines rely on spiders or robots to crawl the Internet for links.

3 Characteristics of Directory Ask the following questions: –Who selects the included Web resources? –Who categorizes the Web pages and sites? –How are the results displayed? –Are the sources rated? annotated? reviewed?

4 Strengths of Directories fewer resources than search engine databases provide rating or annotation of resources increase probability of finding relevant results

5 Disadvantages arbitrary hierarchical arrangements infrequent updates subjectivity of rating and annotating resources

6 Using the Yahoo Directory Go to Yahoo click on Science follow appropriate links to Human Genome Projects.

7 Using Directory Search Go to Yahoo home page click on search and enter “Human genome project”

8 The First Step: Evaluating Your Information Needs Types of information most likely to be found on the Internet Some reasons why the Web won’t have everything you’re looking for Choosing the best tool to start with A checklist to help you choose the right tool

9 Finding Information Gems in Virtual Libraries Virtual libraries are directories that contain collections of evaluated resources that have carefully selected by information specialists. Subject guides, reference works, and specialized databases, are most likely found in virtual libraries. Two popular virtual libraries are the Internet Public Library, and the Librarians’ Index to the Internet,

10 Searching the World Wide Web: Using Search Engines Search engines use computer programs called spiders or robots to gather information on the Internet. The information is kept in a database that is searchable. Two popular search engines are Google, and AltaVista,

11 Search Engine Similarities Search engines list results by some type of relevancy ranking scheme. Two common search features are Boolean searching and phrase searching.

12 Search Engine Differences Size of the database Search options Update frequency Ranking of search results Special features (images, news, and so forth)

13 Using Several Search Engines Simultaneously: Meta-search Tools Some allow you to search several search engines simultaneously. Some supply lists of databases that can be searched directly from their pages. May provide a good way to keep up with new search engines.

14 Task Explore the Directory of NPR – describe its organization Now look at a web library. Describe its organization Find the Kelly book value of my car: a 1998 Honda Civic CX.

15 Content Issues: Pornography, Free Speech, Censorship, and Filtering Free speech vs. censorship Communications Decency Act of 1996 Filtering and blocking devices

16 UW libraries Top 20 Databases with links

17 Summary links for UW libraries reference materials

18 Top level, second level and third level classifications of a collection

19 National Public Radio (NPR) home page

20 The NPR home page Programming pull-down menu What are the top level classifications?

21 The NPR programming hierarchy tree How many levels in the hierarchy?

22 The Google search engine’s advanced search view

23 Restricting the Thai restaurants “hits” by eliminating any page containing the word review.

24 Making Effective Queries Queries use the three logical operators worda AND wordb -- both words must appear worda OR wordb -- either word may appear NOT worda -- the word is prohibited from appearing Google has separate windows for each When 1 window is available, write a formula (Lincoln OR Jefferson) AND NOT Memorial wordawordb Which parts of the diagram do the operators cover?

25 The Burmese mountain dog page Does this page seem legitimate?