Overview of Modern Search Strategies
|The research literature in the United States
and abroad has been expanding exponentially. This introductory lesson
and the following nine Search lessons (S-2 to S-10) will help you find
what you need efficiently.
What is a Good Search?
The answer depends on the purpose of the search. For a research paper in a masters degree course, it often is a search that locates several authoritative studies on the topic. For the literature review of a dissertation, a good search locates at least most of the first-rate research literature on the topic, perhaps some additional scholarly and professional literature on the topics, and perhaps some first-rate literature on topics closely related to yours.
It is rare that you can find a search tool and target the search so well that it finds all that you want and little else. If you target narrowly, you are likely to miss some valuable literature. If you do a broad search, you may find thousands of citations, most of which will not be relevant.
Which Search Tools Are Best?
There are hundreds of tools for searching the social science literatures. Most are now available on the Web. Web search engines like AltaVista, Excite, HotBot, NorthernLight, and Yahooallow you to search for literature on the Web, but only a small portion of the research literature is currently publicly available on the Web. Indexes to the scholarly literature in a given discipline, such as ERIC for education and PsycINFO for psychology, provide broad and deep coverage of the literature in their field, but generally provide only citations and abstracts online, rather than the full text of the reports. ABI/Inform provides similar breadth and depth in the areas of human resource development and management, and does provide the full text for many of the indexed journals. UMI Dissertation Abstracts indexes and provides an abstract of most North American doctoral dissertations. A variety of other search tools can also be useful, such as Associations Unlimited, GOVBOT, the Library of Congress Catalogue, and PolicyFile.
The several Search lessons on this Web site offer instructions in how to use the search tools that are most useful for locating the research literature in the fields of education, human development, and human resource development. These tools can also be useful when searching related fields in the social sciences. Some of the described tools are publicly accessible without charge on the Web. Others are available only through libraries or other organizations that subscribe to them. All the tools described in the following Search lessons were available in Fall 1999 either publicly or privately to the The George Washington University community through the Gelman Library web page at www.gwu.edu/~gelman.
How Can I Appropriately Target My Search?
The following is a good strategy for targeting a search, and it is usually best to undertake the steps in the order that they are listed. Steps (1) – (5) are usually sufficient when preparing a paper for a masters degree class. Steps (6) – (7) are generally expected for reviews of the literature that are part of dissertation research.
The simplest searches use a single word and often yield an unmanageable number of hits. Complex searches use multiple words, but the complexity arises not from the number of words, but rather the logical relationship you intend to specify among them and by the syntax that the search tool requires for representing that relationship. To complicate matters, the various search tools differ some in the syntax that they require.
There are five common relationships between multiple words in a search statement. They are described in order from those relationships that result in a broad search to those that result in a narrow search.
“OR” relationship: This means that you want to find resources that are indexed by any of the words in the search term. EXAMPLE: test OR books -- This will find all resources associated with the term "test" and also all associated with the term "books". Some of the found resources will be associated with both terms, but some will have only one of them.It is possible to combine three or more words with two or more relationships. For instance, special education AND teacher NEAR preparation.
Important Note: Not all search systems support all the above five search relationships. Not all specify the relationships with the terms indicated above. Finally, when two or more relationships are specified, the order in which they are executed will affect the results, and that order will depend on the search tool and perhaps how you exercise the option to specify the order. When you need to use compound search statements, make sure to read the documentation for the search mechanism to see how to correctly specify the search.
Domains of the Search
Searches for literature often can search different parts of the database records for the indexed resources. These parts are described in the order from those that usually result in a narrow search to those that usually result in a broad search.
Search specified citation fields: This scans citation fields such as those for title, author, classification codes, and descriptors. Some search systems refer to descriptors as "index terms" or "keywords".Not all search systems permit all four of the above indicated domains of the search. Various systems have different citation fields. Occasionally a search of descriptors will actually result in a broader search than a search of the full text, even though rarely are more than 20 descriptors assigned to a report; that will happen if a human indexer realizes the report is relevant to a topic that is never mentioned in the report, and assigns it the descriptor for that topic.
"Wildcards" and "Truncation Symbols"
Computers are literal. If you search for "elementary schooling" they will ignore phrases like "elementary school," and "elementary schools" unless told to do otherwise. This is not a problem when a human indexer assigns a descriptor from the search system thesaurus, because the thesaurus will exclude trivial variations of a term. But it is a problem when searching titles, abstracts, and full text. Many search tools allow you to use "wildcards" or "truncation symbols" to indicate the search should include all possible prefixes and/or suffixes of a specified root word. The recognized symbol various among the search systems.
The following are several fixes that may help when you encounter too few or too many hits. Note that not all search tools permit all of these fixes, and each has its own requirements for how searches with multiple terms must be specified:
Too few hits:
1)Check the spelling and punctuation of your search term.
6) This is not a serious problem when using most web search engines because they list the hits in order of their apparent "relevancy" for the specified search; if the first 20 are not relevant, the search needs to be re-stated. Some other search tools do not currently list the hits by relevancy, so if there are thousands of hits, you will want to re-run a narrower search.
This is the first of ten brief lessons on searching for scholarly and professional literature. The other lessons are indicated below. For modest competency, each person should do Lessons S-2 and S-7, and the one most appropriate of Lessons S-3 to S-5. Doctoral students should also do Lesson S-6. The other Lessons will increase your productivity as a student and scholar, but are not essential for searching the literature.
Lesson S-2: Web Search Engines--to get a "quick" take on a topic
Last Update: June 26, 2000