What is Metasearch Engine?

The Metasearch Engine is a search engine that combines the results of various search engines into one and gives one result. It can also be stated as an online information retrieval tool. 
The Metasearch Engine was developed because individual search engines were prone to spams due to people trying to raise their website ranks online. The Search engine visits several websites and creates a database of these sites. This is also known as indexing. Any search engine answers several queries every second. 
The metasearch engines run the queries on most other search engines and in turn reflect the result in the form of the summarization of such sites. 

History 

• It was developed by Daniel Dreilinger at Colorado State University. He developed Search Savvy that searched 20 websites to give back one result.
• MetaCrawler was developed by a student at the University of Washington named Erik Selberg. It was an advanced and updated version of the Search Savvy. It was not as good as the individual search engines.
• In the year 1996, HotBot was created which was faster than its predecessors and could search within their engines’ search results. It was later simplified to serve as a search interface built on the official site of Lycos.
• The year 2000 saw HumHaiIndia.com which was India’s first meta search engine that was developed by Sumeet Lamba. It was later called Taaza.com

Need for Metasearch Engines

The Metasearch Engines were developed to cover the entire web, unlike most search engines. Individual search Engines try to spam people to enhance their page rankings. This is an illegitimate way of promoting. The individual Search engines are unable to find results from other search engines. This is when the Metasearch Engine comes handy. This also supports multiple formats, unlike individual engines. The meta search engines seem effortless.

The Metasearch Engine Architecture

1. User Interface: The user interface of the Metasearch Engine is similar to the look and feel of the individual search engines like Google and Yahoo. It even has options to search on the basis of types and categories and also of which search engines it must use to write back the result.
2. Dispatcher: The dispatcher has the work of query generation.
3. Display: The display uses the queries to write back the results on the screen. It uses methods such as page ranks, parsing techniques, cluster formation, and stitching to give the desired result.
4. Personalization: The personalization in other words is being user-specific. This involves comparing the results with each other.

Operations of the Metasearch Engine

A metasearch engine does not create a database of itself rather it creates a federal database that is actually an integration of the databases of various other Search Engines. 
The 2 main ways of operations involved are :

1. The architecture of Ranking: Various search engines have their own ranking algorithms. A metasearch engine develops its own algorithm where it eliminates duplicate results and calculates a fresh ranking of the sites. This is because it understands that the websites which are highly ranked on major sites are more relevant and would thereby provide better results.
2. Fusion: Fusion is used to create better and more efficient results. Fusion is divided into Collection Fusion and Data Fusion. The collection Fusion deals with search engines that contain unrelated data. The data sources are then ranked based on their content and the likelihood of providing relevant data. This is then recorded in a list. The Data Fusion deals with the search engines that have indexes for common data sets. The initial ranks of the data are compared with the original ranks. A process of Normalization is applied using techniques such as the CombSum algorithm.

Examples of Metasearch Engine

• Dogpile is a metasearch engine developed by InfoSpace LLC. It writes back results from the individual search engines of Google and Yahoo. It combines the search results of text, images, new, etc.
• Sputtr is comparably one of the best meta search engines that combines the results from various popular search engines like Google, Yahoo, Bing, Ask.com, Twitter, Facebook, YouTube, LinkedIn, IMDb, Slashdot, Dictionary.com, About.com, New York Times, etc.
• Another popular site is Trivago, a hotel booking site that mentions this concept in its advertisements. It gives back results from over 100 other hotel booking sites including Booking.com, Airbnb, Expedia, Trip.com, and Agoda. Trivago can be visited at www.trivago.com.

Advantages of Metasearch Engines

1. The meta search engine searches for all the search engines at once hence individual search is unnecessary.
2. As a very user-friendly toolbar that can be easily downloaded.
3. Searching for the white pages and yellow pages are allowed in the metasearch engine.
4. The metasearch engine comes free of cost. Its services are similar to those offered by other search engines.
5. The users can customize the metasearch engine according to their preferences.
6. The results offer coverage data that include more information than results by individual sites.
7. It reduces the workload of the users by allowing comprehensive results in very little time skipping the time and toil of searching for results in the individual sites.
8. Metasearching is a better alternative to searching if getting an overview or quick results is the motive.
9. The Metasearch engines provide a means of hiding the IP addresses form the searches. This provides a lot of security to the user. This is the reason why the French Government uses Qwant (metasearch engine) for its operations.

Disadvantages of Metasearch Engines

1. The meta search engine is not capable of Parsing.
2. It is not as popular as other searches like Google and Yahoo search engines.
3. The meta search engine is not capable of fully translating the query syntax.
4. Its reliability is comparable to the other search engines.
5. They usually prioritize the pay per click types of links before the more relevant search results.
6. The results usually incorporate up to 10 links from a particular site leaving out important links from major sites.
7. The number of hyperlinks provided is limited thereby giving incomplete search query results.