1. 1 Searching the World Wide Web CMP 101 Introduction to Information Systems L02. Internet Search

2. 2 What is the World Wide Web? Billions of Documents –Accessible via the Internet –Viewed by a web browser. Web documents contain hyperlinks –Allow readers to jump from one web document to another –Gateways to audio and video broadcasts, animations, and more.

3. 3 What is a Search Engine? A collection of software –Locates words on web pages –Ranks and indexes the words –Creates a database that you can search. When using a search engine, you search the database that has been created (not the Web).

4. 4 How Does a Search Engine Work? Robots, Spiders, Crawlers – Oh My! –visits web pages –collects words and hyperlinks –gives words to the search engine for ranking and indexing –differing strategies for crawling yield different results

5. 5 How Does a Search Engine Work? Ranking and Indexing –Meta-information the number of times a word appears on a page the word’s location on a page other much more sophisticated information. –differing strategies yield different results

6. 6 Subject Directories Categorical listing of topics with links to individual web sites. Created with the help of human editors Editors rate and rank the sites Good for narrowing down a topic or browsing a large list of topics. Examples include: Yahoo! Directory (dir.yahoo.com), and Gigablast (gigablast.com).

7. 7 Individual Search Engines Create and maintain a database of indexed and ranked words for searching. Good to use if looking for specific information about a topic. Examples Include: Google (google.com), Yahoo! Search (yahoo.com), and Ask (ask.com).

8. 8 Metasearchers Searches multiple individual search engines Presents results in one convenient list. Good to use to get a feel for how much information is available on a topic. Examples include Dogpile (dogpile.com), Mamma (mamma.com), and Clusty (clusty.com).

9. 9 Search strategy kickoff Determine your needs: What are you looking for? Type of searchExamples Broad range of topics in a specific category Subject Directory  Astronomy  Football A lot of information about a specific topic. Meta-search engine  Aurora Borealis (Northern Lights)  Indianapolis Colts Specific facts Individual Search Engine  Aurora Borealis particle speed  Peyton Manning’s passing statistics

10. 10 Basic Search Techniques Be specific Put words in the order you would normally expect them to appear. Avoid using common words. Consider synonyms. Use search focus options: (i.e. images, videos, or blogs).

11. 11 Advanced Search Techniques Boolean logic (AND, OR, NOT): –Boolean AND Include all words. Narrows your search. –Boolean OR Include any of the words Broadens your search. Useful for synonyms. –Boolean NOT or AND NOT Excludes words Narrows your search

12. 12 Advanced Search Techniques Implied Boolean operators (+, -) –Used in place of the Boolean AND and Boolean NOT. Phrase searching (“ “) –Place quotes around a phrase. –Returns documents where the words appear as a phrase (side by side). Wildcards (*): –Used for plurals, alternative endings, or alternative spellings,

13. 13 Advanced Search Techniques Advanced search form –With all the words: Same as using the AND or plus (+) operator. –With at least one of the words: Same as using the OR operator. –With the exact phrase: Same as using quotes. –Without the words: Same as using the NOT or minus (-) operator.

14. 14 Analyzing results Scan through the first five to ten pages of results. Consider synonyms. Use the NOT or minus (-) operator. Broaden your search. Narrow your search.

15. 15 Odds and Ends Search engines ignore some pages. –dynamic (created on demand) such as a request for account information, –require registration or a login (like the Wor-Wic research databases). database not always up-to-date.

16. 16 Odds and Ends Search within a site. Search for individual words or phrases on a page –Edit > Find on this page… on the menu –Search List arrow, Find on this Page….