blog 2

What are the advantages and disadvantage of using searh engine?
answer:  there are three very compelling advantages of most search engine.

1.The indexes of search engines are usually vast, representing significant portions of the Internet, offering a wide variety and quantity f information resources.
2.The growing sophistication of search engine software enables us to precisely describe the information that we seek.
3.The large number and variety of search engines enriches the Internet, making it at least appear to be organized.

Disadvantages.
answer:

1. 
   
Regardless of the growing sophistication, many well thought-out search phrases produce list after list of irrelevant web pages. The typical search still requires sifting through dirt to find the gems.  

2.Using search engines does involve a learning curve. Many beginning Internet users, because of these disadvantages, become discouraged and frustrated.   
  
The comparison between a individual search engine and a meta engine is that they both compile a data base of information and they both gather data.
The contrast between a individual search engine and a meta search engine is that Search engines obtain their data from information contained on individual web pages while
A meta search engine is similar in that it also uses a spider or crawler program to gather data, however it doesn’t index this data. Instead of collecting information directly from individual web pages and storing it, the meta search engine uses the information already collected by other search engines to satisfy your search query

When is it appropriate to use a search engine?
Usually when you need information on a very detailed or multifaceted subject, a search engine will give you not only more information, but also the most precise and up-to- date information possible.
When is it appropriate to use a search/subject directory?
When you do not know how to use the broad topics and you don't know how to find a good sites on a particular topic. 

When is an invisible web or deep web?
Is it some kind of Area 52-ish, X-Files deal that only those with stamped numbers on their foreheads can access? Well, not exactly. The term "invisible web" mainly refers to the vast repository of information that search engines and directories don't have direct access to, like databases. Unlike pages on the visible Web (that is, the Web that you can access from search engines and directories), information in databases is generally inaccessible to the software spiders and crawlers that create search engine indexes.
How do you find an invisible web?
These types of pages used to be invisible but can now be found in most search engine results:

• Pages in non-HTML formats (pd f, Word, Excel, PowerPoint), now converted into HTML.
• Script-based pages, whose URLs contain a ? or other script coding.
• Pages generated dynamically by other types of database software (e.g., Active Server Pages, Cold Fusion). These can be indexed if there is a stable URL somewhere that search engine crawlers can find.

Why are these web pages not available in search engine or subject directories?
 The invisible Web offers the best outlet for searching and retrieving content.
The invisible Web is a wealthy source of online documents that are not suited to be part of the Web search tools because invisible mainly refers to the vast repository of information that search engines and directories don't have direct access to, like database. therefore it is not available in search engine or subject directories.