CHOOSING A SEARCH ENGINE
Search engines are used to perform keyword searches in large databases of information culled from the Internet. To effectively use any type of search engines, it is important to understand what they are, how they work, and how they differ. When searching for sources to use for research purposes, note that the online databases supplied by the Kinlaw Library through www.asbury.edu/library and the materials in the Library Online Catalog have already been carefully evaluated by librarians. Librarians have also reviewed the web sites listed on the Resources by Subject pages at: http://www.asbury.edu/library/ Those resources are recommended to be used in conjunction with general searches done on the Internet.
Search engines can be grouped into four distinct categories (active, passive, meta, and specialized). Each search engine will perform differently based on its underlying techniques. It is important to know how a search engine works as that will affect the types of results that are produced. In the boxes to the right are listed the four types of search engines with examples for each type.
Some places have pre-evaluated and grouped web sites. These are usually vetted for the quality of the information they will contain. Then they are organized into some kind of subject structure.
Digital Librarian - this is a listing of pre-selected sites. Arranged by subject.
Berkeley has a great chart looking at three large search engines - evaluate them: http://www.lib.berkeley.edu/TeachingLib/Guides/Internet/SearchEngines.html
What are the differences? Which one is better for your search? Why should you choose one or the other? Look at these sites for details.
Meta search engines do not create their own databases. They rely on existing active search engine indexes to retrieve search results. In a meta-search, keywords are submitted to the individual search engines and they are searched simultaneously. Since most meta-search tools only retrieve the top 10-50 hits from each search engine, the total number of hits retrieved may be considerably less than found by doing a direct search on one of the search engines. Some meta-searches offer the ability to customize which search engines are queried. The result list will be sorted according to ranking features or in some kind of lumping format. Some "smarter" meta-searching technology includes clustering and linguistic analysis that attempts to show themes within results, with some fancy textual analysis and display that can help you dig deeply into a set of results. Use these with caution and be sure to check the features of the meta-search engine before using.
Active search engines rely on computerized retrieval mechanisms. Referred to as "spiders", "crawlers", or "robots", these mechanisms visit Web sites and retrieve relevant keywords to index and store in a searchable database.
Passive search engines, often referred to as directories, are human controlled and do not roam the Web directly. They rely on individual submissions that are reviewed and indexed by subject category.
Specialized search engines offer additional features that active, passive and meta search engines do not provide.
RedZ - http://redz.com/home
Ask - http://www.ask.com
One Page Mega Search - http://www.bjorgul.com/
Visual Display of Search results - http://www.oolone.com/index.aspx
Privacy when searching - http://www.duckduckgo.com/
Different search ranking - https://www.blippex.org
Search for people - https://www.pipl.com
Computational knowledge engine - http://www.wolframalpha.com