DIRECTORIES AND SEARCH ENGINES

Many ways to search the Internet by subject exist. Two of the common ones are Directories and Search Engines. Simply, Directories categorize web sites into predetermined subjects. Search Engines search the Internet for the words you ask it to.



Characteristics of Directories

• Examples of Search Directories: Yahoo, Magellan, MiningCo.Com., Scout Rep[ort Signpost, WWW Virtual Library
• Topical lists of selected Web resources are organized by predetermined subject categories and arranged hierarchically (from most general to most specific, for example Sports as a subject category and football listed under that category)
• Created and arranged by humans
• Two ways of searching
  1. Browsing
  2. Keyword searching
• Searching is done only in the titles of web pages, the URL's and sometimes the annotations

Use Directories for

• Broad topics
• When you don't need EVERYTHING on the Internet on your subject.
• City, regional, state- specific information
• Organizations pages, events advertisements or place or product information

Directories

Advantages	Disadvantages
Can provide better results as people are involved in identifying and describing sites Fewer results Less repetition More informative descriptions than search engines	Databases are small compared to Search Engines Maybe difficult to find answers to specific questions Not automatically updated when sites of pages change Many directories do not evaluate the quality of a site

• Examples of Search Engines: Google, AltaVista, Excite, InfoSeek, Northern Light, Lycos
• "Comprehensive" and interactive index to the Internet
• Cosist of three parts
  1. Spider
  2. Database
  3. Search engine software
• Fully automated; no human intervention
• NOT searching the actual web in real time ie. the moment you are asking a question
• NO SEARCH ENGINE INDEXES ALL OF THE RESOURCES ON THE INTERNET
• Little overlap among search engines
• No selection criteria
• Need to use several search engines

Search Engines

Advantages	Disadvantages
More comprehensive tan directories Good for identifying specific information Most index the entire Web page Can perform specific searches using fields and limits	Often retrieve vast numbers of hits, many do not relate to your topic Results are not often at the top of the list Rely on automatically generated summaries Results often include many duplicates Do not discriminate between materials in terms of their quality