The Internet October 30, 2007

The Internet URL’s Search Engines Boolean Operators Internet Searches Scavenger Hunt

URL’s The address of a web page URL = = Uniform Resource Identifiers –Universal Resource Identifiers –Uniform Resource Locators 31 billion web pages with URL names!!!

URL’s 6 Examples ftp://ftp.download.com/public telnet.//freenet.ecn.ca gopher://

URL’s Some general rules: Never has any spaces in it For the most part it is all lower case Not the same as an address Always starts with protocol prefix Eg. - most browsers will type that for you Other internet protocols Eg. ftp:// gopher:// telnet:// irc://

ANATOMY of a URL

Search Engines 3 kinds of search engines 1. Crawler Based 3.Hybrids 2.Human Powered Directories

Crawler Based Search Engines Eg. Google Create listings automatically Crawl or spider web produce list that we go through These engines will eventually find any changes you make to your site and will update the index accordingly

Human Powered Directories Eg. Open DirectoryOpen Directory You submit a short description to the directory for your entire site Editors can also write a summary for a site they view as well When you search a directory you are only searching the descriptions, NOT the sites

Hybrid Search Engines Combine the best of both worlds! Eg. MSN search Usually these favour Crawler or Human, they’re never ½ and ½. MSN favours human powered over crawler

How do Search Engines Work? 3 Elements 1.Spider (aka crawler) Visits web page, reads it and goes to other pages that are linked on the site Site was “spidered” Returns every month or two to check for any changes

How do Search Engines Work? 1.Spider to Index Spider  Index or Catalog A site will not turn up in a search until it has been indexed or catalogued.

How do Search Engines Work? 1.Search engine software Sifts through the index to find any matches to a search Takes any matches and ranks them in order of relevance for you

Searching the Net What do you type into the Search bar so you will find what you’re looking for???

Searching the Net Boolean Operators

Searching the Net The use of words to show the relationship between two items AND OR NOT

Searching the Net Can also use “ ” (Quotes – not smiley) Quotes will _______ your search because the words need to show up side by side Quotes also make your search more direct and you tend to get better results!

Searching the Net Using + and – signs also helps your search! + tells the search engine which keyword you think is most important + must have a space in front of it and must be attached to the word it relates to - removes words that you do not want included in your search results