Databases


 * Introduction to Web Databases**



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=Overview of Specialized Databases=

There are several different types of specialized databases.




 * a **bibliographic** database includes citations that describe and identify titles, dates, authors, and other parts of written works; it doesn't usually contain the full-text of the works themselves, although if an article is available for free, a link will be provided to it; examples are **PubMed** and **WorldCat**
 * a **full-text** database on the other hand, includes the entire text of the indexed works; it can contain books, articles, poetry, and more and is searchable by keyword; a full-text database differs from a bibliographic database in that it includes both a description //and// the work itself; an example of a full-text database is **[|Bartleby.com]**
 * another type of specialized database is a **numeric** database which contains statistical data, usually in chart or spreadsheet formats; and example of a numeric database is the **Statistical Abstract of the United States**
 * another type of specialized database is a **directory** database; they usually provide brief information about people, businesses, or places
 * there are also **multimedia** databases which, videos, podcasts, and more


 * Proprietary Databases**

There are hundreds of **proprietary** or **commercial** databases on the Web, but these are available only if you or your organization has purchased them

Proprietary databases have certain value-added features that databases in the public domain do not have. Here are some examples:


 * Proprietary of commercial databases often contain information that is under copyright restriction. You'll be prompted to pay or enter a password to see full text. Your library may have the right to access the database, so it's important that you check with a librarian before you pay for an article that you need
 * Proprietary databases allow you to download information easily
 * Proprietary databases often index material that others do not; the information is distinguished by its uniqueness, its historical value, or its competitive value (for example, private company financial information)
 * Proprietary database systems are more responsive to their users. Because they charge fees to use, they are more apt to provide training and other user support, such as the distribution of newsletters that update their services. There are also databases on the Web that are free to the public but charge for the full text of the articles, for example, [|High Beam Research]. Many newspaper archives work the same way. You can search the archive, but if you want a copy of the newspaper article, there is a fee involved.

=Information in Specialized Databases Is Often Not Accessible Via Search Engines=

The major search engines build their databases by collecting URLs that exist on the Web. The Web pages that are attached to the URLs are then indexed. When you type a word or words in a search engine's search form, you retrieve a list of URLs that already exist in the search engine's database. To put it simply, a search engine typically cannot search a specialized database because of the following reasons:


 * A database usually cannot search another database without some very special programming. The search engine you are using may come across a specialized database but then may be stopped from going any further because the special database has a search form that requests information from the user. For example, you wouldn't look in Google to see what books are in your library; you'd look in your library's Web-based catalog.
 * Many specialized databases contain information that is retrieved dynamically every time a request is made, and the URLs that are generated are different each time. A search engine usually cannot build its database with URLs that may work today and not tomorrow.
 * While search engines such as Google have made great progress with their attempts to reach the invisible Web, by indexing PDF files and including some dynamically generated Web pages in its search results, there are still some types, such as audio and video files, that aren't always accessible in a basic search

=How to Find Specialized Databases=

There are thousands of specialized databases on the WWW. How do you find them?


 * You can go to a search engine and type in the kind of database you're searching for along with the word **database**. For example, each of these search expressions typed in Google's search form provides excellent databases in the areas requested:


 * medical database**
 * Flags database**
 * "zip codes" database**


 * Directories are often the best sources to use when looking for specialized databases. Following is a list of some of the most popular ones:

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 * Beaucoup**

Beaucoup lists more than 2,500 specialized databases and directories and also serves as a meta-search tool.

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 * The Digital Librarian**

Maintained by Cortland, NY librarian Margaret Vail Anderson

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 * ipl2: Information You Can Trust**

A virtual library that provides a good starting point for finding reference worlds, subject guides, and specialized databases.

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 * Intute**

Intute provides access to the very carefully selected Web resources for education and research. All sites are evaluated and selected by a network of subject specialists.

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 * LibrarySpot**

Collects links to quality references resources and provides links to more than 2,500 libraries around the world.

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 * Open Directory Project** and **Yahoo! Directory**

Two of the most comprehensive directories on the Web; these are also good places to find subject guides and specialized databases.

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 * The Scout Report**

The Scout Report is a good way to keep up with new research tools, especially specialized databases. You can view its weekly report and its archive of previous Scout Reports on the Web.


 * Source:**

Hartman, Karen and Ernest Ackerman (2010) Searching and researching on the Internet and the World Wide Web. Sherwood, OR: Franklin, Beedle & Associates.