LibGuides: Library FAQ... (Frequently Asked Questions) and more!: Searching Databases and Journals

Searching Databases

The first step in searching is to determine exactly what your topic is, and the keywords or descriptors (the latest name for official subject headings) under which you might find citations for the topic. For example:

The effects of diet, sugar, or food additives on hyperactivity or ADHD (Attention Deficit Hyperactivity Disorder)

You should write down keywords in groups of synonyms that express the main concepts in the search. In this search, there are two groups of synonyms:

Hyperactivity
ADHD
Attention Deficit Hyperactivity Disorder(s)
Attention Deficit Disorder(s)
Diet(s)
Dietetic(s)
Sugar
Food Additives

Truncation

In some of these terms, there are singular and plural possibilities for each term, such as diet or diets. To handle this, electronic databases allow you to use truncation, a way of inputting the terms which allows for alternative forms of the terms.

Boolean Search Operators

There are three basic boolean search operators: OR, AND, NOT. These do not have to be input in upper case, but can be typed in lower case. In general, you do not have to capitalize any words when typing search terms.

OR links together keywords which are synonyms, and sees whether any of them is in a database record (a single citation).
For instance:
diet* or dietetic* or sugar or food additive*

might find diets in article 1, sugar in article 2, food additives in article 3, and dietetic in article 4. As you add more terms together with "or," the number of search results usually enlarges.

AND compares the search results of any two terms or sets of synonyms, and lists only the articles which contain both terms or at least one term from each set of synonyms. For instance, if we were to put in the terms used above to illustrate the synonyms for the large concepts, we could type in two sets of terms:

hyperactivity or adhd or attention deficit hyperactivity disorder* or attention deficit disorder*

The output (called a "set") might be: s1 3578 (hits)
diet* or dietetic* or sugar or food additive*
The output for these terms might be: s2 758 (hits)
We then can use the AND operator to combine these sets:
s1 and s2 54 (hits)
This set of 54 hits might contain these citations:
article 1 contains: (hyperactivity AND sugar)
article 2 contains: (adhd AND sugar)
article 3 contains (attention deficit hyperactivity disorder AND diets)

NOT (sometimes input as AND NOT) is used to exclude a search term or previously looked at set of citations from the current set of citations that you want to retrieve. For instance, if you looked at the s3 below, and then decided to input "sugars" to possibly find more articles, you could type in s1 and sugars, resulting in a s4. Then you could type in s4 not s3 to exclude the articles you previously looked at.

hyperactivity NOT sugar would find all the citations which included the word hyperactivity, but would exclude any citations which included the word sugar.

Sets and Search History

When you input sets of synonyms with the OR operator, a "set" is output which can be used with OR, AND, or NOT operators to combine with other sets to produce various results. The searching software from different database vendors labels these results in slightly different ways, so you will need to adjust accordingly.

You can re-input these sets numbers in the following way when making new search statements: r1 and r2, or #1 and #2, or s1 and s2.

As search results build up, search sets are listed which can later be reused or "tweaked":

s1 3578 hyperactivity or adhd or attention deficit hyperactivity disorder* ...
s2 758 diet* or dietetic* or sugar or food additive*
s3 54 s1 and s2
s4 25 s1 and sugars
s5 15 s4 not s3

This listing of search results is called the search history.

Nesting

This is a way to include sets of synonyms in parentheses ( ), and type the AND operator between the sets, so that you only have to input one line (instead of inputting several search statements, with several set numbers). This is especially useful in databases which only allow you to type in one line for a search statement, and do not let you use a search history. Here is a sample:

(hyperactivity or adhd or attention deficit hyperactivity disorder* or attention deficit disorders*) and (diet* or dietetic* or sugar or food additives)

This method allows you to reuse the results of the entire search statement only. Individual words or subsets would have to be typed in again as illustrated in the example given above in the "Sets and Search History" section. You would have to re-input the sets of synonyms as we originally did it above in s1 or s2.

Another example of nesting which also shows how the NOT operator could be useful is this: you want to find articles about social or special interest clubs, but you don t want articles dealing with health clubs, sports clubs, or athletic clubs. Type in:

clubs not (athletic or sport* or health or golf or baseball or tennis or hockey or football).

This should result in articles related to your topic. Or, you could be more specific and input:

clubs and (social or dog or animal or cat or fraternal)

Using the Thesaurus Feature

In computer vocabulary, a thesaurus is the list of official subject terms ("descriptors" or "subject headings") that the indexers assign to the articles as they enter them into the database. Some OhioLINK databases have thesauri built into them. When you bring up these databases (such as Academic Search Complete or CINAHL), there is usually a tab above the search box marked "subject terms" or a check box for "suggest subject terms". This means that when you type in a keyword, OhioLINK takes you into the thesaurus, and matches your terms with the correct subject term/descriptor the database uses. Sometimes a heading will display with these choices behind it:

Search - find records with this term as a subject heading.

Focus- find records with this term identified as a major subject heading

Explore - view this subject heading's hierarchical or "tree" view in the thesaurus

Expand - find records with this term as a subject heading or with a subject heading of any narrower term in the thesaurus.

Expand/Focus - find records with this term as a major subject heading or with a major subject heading of any narrower term in the thesaurus.

In most cases, you will want to click on "search." (You do not have to remember these definitions; they are displayed at the bottom of the thesaurus search results screen.) Scope notes provide additional details about a term.

For additional help with specific databases, ask the reference librarian.

Evaluating Web Content

A PDF from University Libraries, University at Albany, State University of New York.

Evaluating Web Content
This guide offers tips for evaluating the quality of content on the Web.

Web vs. Library Database Comparison

Authority	Varies at best. Difficult to verify. Cannot limit to professional, scholarly literature. Information on the Web is seldom regulated, which means authority is often in doubt.	Easy to determine. Most databases have scholarly/peer-reviewed filter or contain only trustworthiness are virtually guaranteed.
Number of Hits	1000’s, sometimes millions of hits, much of the same information repackaged or duplicated. Duplicates are not filtered out.	Dozens to hundreds of hits (sometimes 1000’s but not 100’s of 1000’s) - a more manageable number, and duplicates can be filtered out
Relevance	Lack of subject focus can result in numerous irrelevant hits – or “junk” – to wade through. Much Web infomation is opinionated and biased. Unlessyou are using a subject-specific search engine, expect “everything and the kitchen sink” in theresults. Quantity ≠ Quality	Focus by subject (business, art, American history) and/or format (journals, books, book reviews), which often means more relevant informationand less time wasted dealing with junk. Information comes from legitimate, quality-controlled souces.
Search Features	Varies by search engine, but often limited. Can limit by document type (.doc, .pdf) or language, but limiting by publication date, format (article, book,etc.), scholarly/peer-reviewed and more is unavailable.	Numerous advanced search features determined by database subject focus, e.g., limiting by publication type, date, language, document format, scholarly/peer-reviewed status. The list of features is as long as the number of databases available.
Access to Published Information	Web information often lives and dies on the Web and can come from anyone with Internet access. Seldom is the information coming from legitimate published sources: magazines, academic journals, books, etc. When it is, the user usually has to pay to access it.	Databases deal only with published information; that is information that originally appeared in print: magazine and journal articles, books, etc. They are more stable than the Web. Through the library’s paid access, all of this information is available to you, the user, for free.

Thanks to the University of Maryland and the University of Dallas for providing the content for this tool.