2. Contents
Basics of Search Engine
What is Search Engine ?
Types of Search Engine
Advantages
Disadvantages
Limitations of Search Engine
3. Basics of Search Engine
1. Store millions of pages in their data base.
2. Sites are included automatically based on a set criteria no human interface.
3. Search features / scope vary greatly from one to another .
4. Good for beginners and experts .
5. Good for searching on a narrow topic.
6. Search for particular types of documents ,files etc. is possible.
4. What is Search Engine ?
The father of search engine is Jonathon Fletcher.
Search is a tool ,which helps in retrieving in information
from the internet .
It indexes the web and accordingly builds its database.
Each search engine has its own set rules to index
websites.
5. Types of Search Engine
Crawler based search engines
Directories
Hybrid search engines
Meta search engines
6. Crawler based search engines
Are search engines that use software programs that are called “spiders”,
“crawlers”, “Robots”, “bots”. These programs can access the webpages
to categorize and analyse them and then add them in the search engine
data base , where any user can find them when searching. The crawler
based search engines are constantly updated with new webpage that
would be available in their database.
Examples:
1. Google
2. Yahoo
3. Ask.com
7. Directories
Are websites sectioned in specific categories by human
editors and are then place in the “Directories” , database.
Examples:
1. Yahoo Directory (www.yahoo.com)
2. Open Directory (www.dmoz.org)
8. Hybrid search engines
Are search engines that use both crawler based searches
and directory searches to obtain their results.
Examples:
1. Yahoo.com
2. Google.com
9. Meta search engines
Are the search engines that combine all the result from
other search engines into one big list.
Examples:
1. Metacrawler
2. Dogpile
10. Advantages of Search Engines
Enable to quick search to vast amount of information from
one search box.
Search on a specific type or piece of information is
possible.
Different types of search engines enable to look for
specific types of Documents.
11. Disadvantages of search engines
Creates information overload
Semantic search is not possible
Privacy and security is of concern
Makes everyone to dependent
12. Limitations of Search Engines
Can not index the entire web. Most of the search engines
can index only between 40% and 60%of the web.
Can not index sites governed by password and developed
using frames.
