All research scientists must learn how to conduct exhaustive literature reviews in their subject disciplines. The guidelines listed below are suggestions that can help lead to that goal. Literature reviews are a time consuming and often difficult task. Below are six steps that may help with the first steps and ongoing work of searching the literature.

1) Start on the World Wide Web

Often the most recent and pertinent articles on a subject may appear through a simple search on the World Wide Web. A review of search results may not only answer your immediate questions, but may also give you ideas of alternative keywords to expand your search. This is perhaps the easiest and most simple means to get started in the literature, but beware of the content you find on many web resources. You can perhaps find more reliable information by limiting your searches to .gov and .edu domains on the web. Be sure to check advanced or alternative search methods on commercial search websites.

2) Search a Bibliographic Database

Most academic and research libraries provide online access to bibliographic databases for their students and professional staffs. There are many science and technology databases, and it is advisable to find out which ones might best suit your needs. The two most frequently used in the earth sciences are GeoRef (produced by the American Geological Institute) and Water Resources Abstracts (Cambridge Scientific Abstracts). Access Science and Science Resource Center are two of the many other databases that may be useful. Many other major science databases are frequently overlooked in the literature review process including many biological, chemical, engineering, and general comprehensive science databases. Note that experienced researchers frequently claim that a database search will typically yield only about one-third or less of the important or relevant references on any particular topic. Digging deeper into the literature takes more difficult steps. GeoRef and Water Resources Abstracts are fee-based services, but many libraries allow you to access them for free. A free geologic map database is available at: http://ngmdb.usgs.gov/.

3) Read the Recent Literature

Reading a variety of recent articles both directly and indirectly related to a research topic is essential for discovering new issues and trends in a new research field. Read, read, READ! And keep reading! Examine the bibliographies of multiple articles. It is essential to build a background knowledge in a scientific discipline to learn about ideas, paradigms, and potential paradigm shifts. It is also important to separate observations from interpretations. Some researchers may not include references to the opinions of those who feel differently about the causes or effects of the phenomena under study.

4) Examine the Popular Literature

After reviewing the science literature, examine the popular literature (newspapers, popular science reviews, and societal review publications). The popular literature often exposes differing opinions that may not be apparent in the published literature. Popular literature guides include resources like Reader's Guide to Periodical Literature or The New York Times Index. Asking an experienced librarian for help will save you valuable time and give you additional ideas and sources to pursue.

5) Return to the Library

Literature reviews are an essential component to ongoing research. Return to the beginning of the research review process frequently, searching the new terms, phrases, and "buzz words" that you discover along the way. Take advantage of interlibrary loan services to get the important resources that are not available in your local library. These are usually available for free and is one of the most valuable services that a library provides.

6) Talk to Researchers in the Field

Don't hesitate to get on the phone, or search the name of individuals conducting research in your field of interest. Write them an e-mail for advice about more current information that may be more relevant to your research interests. Consider attending a conference where individuals of the discipline get together.

There is always the possibility that nothing appropriate to your research needs exists. Also, it is always important to review your research hypotheses. Could you ask your research questions in another way? Are their other research avenues that you might explore? When it comes to digging through a library collection, persistence improves your chances of a successful and productive literature review.

Author: Phil Stoffer, Western Earth Surface Processes Team, US Geological Survey