Online Research - Section 4 - Database Searching

Database Searching

Databases are valuable research tools. You can access them off CD-ROMs or the Internet. Most have been collected on a specific subject. Many are statistical in format, while others contain full text of articles or books. Some contain information produced by third parties. Many databases can be accessed only with a password. Some vendors offer a limited version that you can access for free, but charge a subscription fee for the full database. All databases have editors and selection criteria for quality control. As a result, they tend to contain more relevant information than found over the general Internet.

All databases tend to be organized in basically the same way, consisting of:

Search box
Subject directory
Thesaurus
Author
Title of publication
Keywords

They may also have help screens, advance features and Internet links. You can access databases either through your library or online through the Web.

Library Databases

Most libraries subscribe to a number of databases. Typically, libraries offer access to periodical indexes of journals. Some will even include complete articles. Libraries also offer full text databases on many subjects, such as psychology, education, history, science, medicine and literature. You will need to determine the best database(s) for your needs. It'll help to check with the reference librarian to find out what you can access and which database best fits your needs.

Two databases commonly available through libraries are Infotrac and Facts on File. Infotrac is a journal and magazine index with many full text articles.

Facts on File is a large collection of facts.

Online Databases

Online databases fall into two categories. Some databases are free with unlimited access and others are by subscription only.

Free Databases

These are often created by government or other public agencies, such as:

National Library of Medicine
U.S. Congress
NASA

Many of these can be found through http://www.lib.umich.edu/govdocs/federal.html:

Subscription Databases

Private brokers who contract with database producers create these. The information is often reprocessed and bundled.

If you are working in a specific field, it may be worthwhile to subscribe. However, libraries often subscribe to several databases. Subscription databases are password protected and assess is limited. To save yourself money, use your local library for access.

Using Databases

Because many databases are password protected, we will use some of the free access ones. The best free databases are published by the federal government. One such database is PubMed. Produced by the National Libraries of Medicine, it is designed for medical professionals. Much of the information it contains is from professional and scholarly publications. It's search structures are complicated, related to medical terminology. We will only look at some basic features.

Help

If you press on the "Help" link on the side bar, you'll get a listing of help topics much like the one seen below:

Tutorial

You will find two of the tutorials particularly helpful. To start, press on the "Tutorial" link on the left side bar. You will be greeted with a screen resembling the one below:

Let's take a look at the "Features Bar" tutorial first. By pressing on this side bar link you should get the following set of pages that describe how best to use the Feature Bar:

If you are interested in exploring this database, you should probably run through this tutorial yourself. The other tutorial worth visiting is the "Search Field Descriptions" which you can access by clicking on this item on the left side bar. You should get a screen similar to the one that follows:

PubMed Search Field Descriptions Tutorial

You'll notice a reference to the Boolean operators we covered earlier. Again, for any database you're planning to use, it is recommended you to run through the tutorial yourself

Example Search

Let's return to our example of gathering resources on Male Breast Cancer and see what we can find by using PubMed. To follow along, open a new browser window with PubMed and switch between these two windows. One caveat: PubMed may have updated their screens since these pages were written, so you will need to use these directions as a guide rather than a perfect representation of what you are seeing.

As you might remember, the search terms that we used were: breast cancer and men. So let's try these terms now by entering them into the search box and then pressing on the button.

The results returned from this search are seen below:

As you can see, there are a total of 1039 items, close to the number we got during our first searches using MELVYL. Rather than sort through the whole list looking for relevant items, click on the "Limits" option right under the search box. You should get a window much like the one below:

In the above illustration, the limits have been set to "Title Word," "Human," "Male," and "2 Years" (for the last 2 years of publications). Also, we're going to be asking for only items with abstracts. When the search is performed again using these limits (by pressing

again), we get these results:

PubMed search results after setting limits

This time, we get a more manageable list of five items. To find out more about a particular item, just click on the author link and you'll get back something like this:

Summary

Although all databases do not work exactly the same as our PubMed example, most do have similar features. Here are a few other databases worth looking at:

Hoovers's Online http://www.hoovers.com/ for commercial entities.
US Census Bureau http://www.census.gov/ for population statistics
California Employment Development Department http://www.calmis.cahwnet.gov/ for labor and employment data

Remember, when first using a new database, run through the help and/or tutorial sections to get the lay of the land. If you are having trouble finding what you need, work with your local reference librarian.