Tuesday, March 13, 2012

How to Use Search Engines?

A Search engine is a tool used to search and retrieve information stored on computer systems, mostly on the Internet. To search for information, the search engine makes use of specific keywords that we type in and returns a list of documents that contain the keyword. The information can be stored within web pages, documents or databases on computer system, or we can search for these documents themselves using search engines. Some of the most popular search engines used today are Google, Yahoo!, Alta Vista, and Lycos.
Search engines help us find the right information from the comfort of our workstations and faster than any other means. For example, there are thousands of documents that we can find on the web on any particular topic, besides scientific papers, journals, and magazines. In addition, we can store and access information in digital form such as photographs, video images, computer games, and so on from the web. The Internet also has free computer software that we can access and download free of cost using search engines.
Types of Search Engines
There are various types of search engines available today. These search engines and their functions are listed in the table below:
Search Engine Type
Web search engines
Used to search information on World Wide Web (Internet)
Enterprise search engines
Used to search on intranets
Personal search engines
Used for searching the contents of a user’s computer files (Desktop search)
Mobile search engines
Is the convergance of search engines and mobile devices such as mobile phones
How Search Engines Work
A search engine provides an interface where a user can search for relevant information by providing certain criteria (keyword or phrase), for which the search engine finds the matching information. There are various steps that search engines follow to help us find the information we need. These steps are given below with their description:
The keyword or phrase that a search engine intakes for a search item is called a query. A query can be either a formal query or a non-formalized query, depending on the syntax used for querying. Formalized queries require a strict, logical, and algebraic syntax. On the other hand, non-formalized queries are less strict with the syntax.
Natural Language search is a common form of non-formalized querying where Web Search engines use natural language processing in some form or the other. For example, instead of entering just one or two words, complete sentences can be used as search criteria.
Typically with all Web search engines, the mose relevant items are placed on top of the list and the least relevant items are placed lower down the order so that the user can easily locate the most relevant item. This is called ranking.
A search may return either items that are exactly matching with the keyword or will return nothing. However, we can also search for items that more or less match the search criteria that we enter. These matching items are then sorted or ranked so that the items that match the most are placed on top of the order.

To provide fast results in case of a search, a search engine will store information in advance on a server about important items of search. This information is called metadata. For example, a search engine may determine and add the title, author’s name, or the number of pages to the description of each book, on a server in the form of an index.
As a result, users can add these details as search criteria with the description of the book, which will enable a faster search. This is because the search engine can now calculate faster the similarity between the query and the set of items stored on the server.

Different Search Options
Simple Search
To search information on a particular topic, identify key concepts related to the topic. These concepts are then used as key words for the search. For example, to find information on the mobile tariffs charged by Airtel, you can enter the keywords “Airtel Mobile Tariffs”.

Boolean Search
A Boolean search requires the use of the Boolean operators AND, OR, or NOT, or a combination of these with the keywords. This helps in getting better search results in contrast to a simple search.
1. AND
Connecting search terms with AND ensures that the search engine retrieves pages containing ALL these keywords, which will help in getting fewer but more accurate results. For example, the key term “Airtel and Mobile and Tariffs” will only return pages that contain all the three keywords.
2. OR
Connecting search terms with OR ensures that the search engine retrieves pages containing ONE, SOME or ALL the keywords. For example, the key term “Airtel or Mobile or Tariffs” will return pages that contain one, some or all the three keywords.
Note: Surround OR statements with parenthesis for better search results.
3. NOT
NOT is used to search for Web pages that contain one word but not the other. For example, Mexico Not New Mexico, will display documents that contain the word Mexico but exclude New Mexico.
4. Implied Boolean: PLUS and MINUS
In many search engines, the plus and minus sign can be used instead of Boolean AND and AND NOT respectively. For example, Alta Vista’s simple search process requires the use of the implied Boolean symbols.
Note: There is no space between the sign and the keyword.
For example, +search +process
Advanced Search
Advanced search provides more effective ways to improve search results compared to Simple and Boolean searches. Some of the advanced search methods are described below.
1. Phrase Searching
Phrase searching is a powerful search technique where a group of words is included within double quotes so that only those documents where these words appear together are listed.
2. Plural Forms
Enter the search keyword as a plural if you want to see the documents with only the plural form of the keyword listed.
3. Alternate Spellings
To see alternate spellings of a word, you can use wild card features with the keyword. For example, Gen* will return pages with words such as Genius, Generation, Gerund and so on.
4. Use of Parenthesis
To clarify relationships between search items, use parenthesis. For example,
(Delhi or NCR) and Companies, will search and display companies in Delhi and NCR.
Steps for Effective Search
For the most effective search and to get the best results, you need to follow certain basic steps. These steps are listed below with brief descriptions.
1. State clearly and briefly what you want to search for.
For example, What are the different Learning Theories?
2. Identify the keywords in the sentence.
For example, What are the different Learning Theories?
3. List synonyms, alternate spellings, and variant word forms of each keyword.
For example, different, various
4. Combine synonyms, alternate spellings, and variant word forms of each keyword.
Combine synonyms with Boolean OR, and place parenthesis around the statement.
For example, (different or various)

Combine keywords with Boolean AND. For example,
(different or various) and Learning Theories
Note: In case of alternate spellings, use the asterisk symbol to indicate different spellings within the statement.
5. Check Spellings Thoroughly
To get accurate search results, check the spellings thoroughly in the keywords. This will eliminate Web pages or documents where the spelling is not the one you intended.
Search Engines: Common Examples and Functions
The following table lists some of the commonly used search engines and their functions and features.
Search Engine Name
• To search for items using specific keywords
• To search for an exact phrase- is very adept at returning relevant results
• Has the largest database of 1.5 billion pages
• Supports Boolean and advanced searches

Yahoo Search
• To search for items using specific keywords
• To search for an exact phrase
The best option after Google
MSN (Live) Search
• To search for items using specific keywords
• To search for an exact phrase
The best option after the above two, is being improved.
Alta Vista
• Provides various powerful search features not found elsewhere
• Provides for Simple and Advanced searches
• Claims one of the largest search engine databases with over 550 million Web sites
• Offers specialty search engines like an image finder, an MP3/audio finder, a video finder, and a people finder

Hot Bot
• Has an index of about 500 million pages
• It supports implied Boolean logic, full Boolean logic, and truncation
• HotBot also offers phrase searches as well as several media-type searches such as audio, video, and images

Microsoft Encarta
Provides information and data for specific questions

Provides information and data for specific questions

Provides information and data for specific questions

Provides information and data for specific questions

Provides information and data for specific questions

Yahoo Directory
Provides overview of a subject

Google Directory
Provides overview of a subject

The Open Directory Project
Provides overview of a subject

Ask IQ
Provides top searches, movies, news, advancing searches of the week

Yahoo Buzz Index
Provides various options, mainly entertainment

Google Trends
Provides various options for search, but not too impressive

Lycos Top 50
Provides listings on various topics

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