A multi-search engine combines many search engines into one unified search engine. It is a fast and comprehensive way of casting a wide net on the Word Wide Web. There are thousands of search engines on the Internet. Although some are quite good, none of them is comprehensive. Some may use a small database to create your result set, some may not be updated regularly, and still others may be quite slow. Thus, you may need to use several search engines to ensure an all-inclusive search result. Multi-Search engines may use from as few as ten to as many as thousands of search engines.

Different approaches used

There are different approaches used to perform and display searches by multi-search engines. Below are the three different approaches:

  1. A basic list of all search engines. This multi-search engine will take the search term given by the user and simply display search results from different search engines in a linear fashion in the same order as they would have appeared if you used the search engine directly. So you will get a page of hits from AltaVista, followed by a page of hits from Yahoo, and so on
  2. Successive searches. Here, a user inputs a search term and may get to choose which search engines to use. The term is then transmitted to the specified search engines. The results will then be displayed for you in a list. The list can only be generated when all the results are obtained, meaning searching is therefore dependent on the slowest search engine.
  3. Concurrent searches. This search engine works the same way as the successive searches but is much faster because it displays results as they appear. It does not wait for all the engines to finish running before displaying results.

Of course, the main advantage of multi-search engines is that you can view a comprehensive list of available Web pages for your search term. Also, multi-search engines are able to do this much faster than it is possible to accomplish manually. However, they do have some disadvantages.

Disadvantages of multi-search engines

Multi-Search engines have the following disadvantages:

  1. Delay. Some may take a while to display their results. You will thus have to wait until the engines referenced decide to return a result.
  2. Dependence on external search engines. Multi-Search engines have to rely on the referenced search engines and cannot refine your search to the given terms.
  3. Dilution of focus. A user is not able to focus a search when using a multi-search engine. It may be difficult to narrow your search effectively because different engines use different codes.
  4. Possible syntax confusion. Because the search is running on different search engines, one must be careful about the syntax they use. Some search engines may not understand advanced syntax and may return bogus results.

Some of the best multi-search engines include the following:

  1. Metacrawler
  2. Dogpile
  3. Savvy search
  4. Metor
  5. MetaIQ
  6. KillerInfo
  7. Mamma
  8. DigiSearch
  9. Ez-Find
  10. FindSpot
  11. Highway 61
  12. The search beat
  13. IXquick