March 9 assignment - Blog 3 - Search Tools

Internet search tools exist in the form of directories, search engines, and metasearch engines.   Prior to our reading assignment, I wasn't aware that there were directories or metasearch engines so it was very interesting to learn about these topics.   

Directories are human-compiled, hierarchical list of Web pages organized by category.  As defined in the Ultralingua Dictionary app, hierarchical means that content is classified according to various criteria in successive levels or layers.    Directories can be a useful way to organize web-based information for easy access by browsing from a general category and refining your search to a more specific category.   The process of searching directories is called "drilling down."  When drilling down in a directory, you leave "breadcrumb trails" that allow you to move back and forth between pages you were at before.   I used DMOZ Open Directory Project and used a search query of "Facebook Marketing for Business."    The results are shown below: 

 DMOZ Open Directory Project Query

The benefit of using a directory is that human editors categorize the information in a logical manner making the search process easier.   The disadvantage to this approach is the time in which is takes the editors of these directories to analyze what pages to include and then do the work to add them to the directory. 

There are several search engines available to perform Internet searches.  These include Google, Ask.com, Bing, Alta Vista, Gigablast, and Yahoo!  There are specialty search engines such as Bizrate (for business), Technorati (for blog lists), and Fact Monster (for children).  Search engines function entirely without human intervention in gathering and indexing the web sites.  Search engines use software called spiders, Bot (short for robot) or web crawlers that browse the web searching for web sites to add to their indexes. Spiders and Bots automatically add URL's and information about web pages to their searchable indexes.   The information that a Web crawler will typically collect to create their indexes are page title, URL, meta tag keywords, occurrence of key words - meaning the frequency of use and where they appear on the page, full-text searching which examines all of the words on the Web page, internal links within the Web page to other pages on the web site, and the number and relevancy of other Web pages that link to that page.  

Web crawlers store information on a database on one or more servers creating an searchable index.  Web crawlers continually search the Web to add updates and new web sites to their indexes.  Web crawlers are used only to gather and update web site indexes.  When you perform a search using the search text box in a search engine, you are not interacting with the web crawler, simply the results of the web crawler that are stored in the index.  

Most search engines will allow advertisers to pay a fee to more prominently display their web sites.   This is called paid placement.  When performing a search on the Web, you enter the keyword or words into the search engine's search text box.  The search engine then takes the query and looks for those keywords in their index.   Once the search engine has found relevant matches to the keywords, it assembles a list of web pages and displays them in a specific order.   Each search engine uses its own formula or algorithm to determine which pages to display and in what order.   The most relevant pages are presented at the top of the list.   Shown below are two searches I performed for Maltese.  One was on Google and the other on Yahoo!    You can see from the results that different pages were presented by each search engine to the exact search keyword.

A metasearch engine is a special type of search tool that generates search results from several search engines by submitting the search to several search engines then combining and displaying the results.