Search Techniques

This tutorial will help you master searching library resources such as scholarly databases—starting with choosing keywords, then putting them together to retrieve accurate results. While general search engines such as Google rely on finely tuned algorithms to arrive at the most relevant results, library resources like scholarly databases require the searcher to have a deeper knowledge of search techniques. Searching using the techniques in this tutorial will set you up for success searching subject specific databases and give you a better sense of the automatic search processes behind general search engines.

Searching Library Resources

Keywords reflect the main points of the question and should omit the non-essential words, such as "What," "Have," or "Does." Words like "Impact" and "Effect" also should not be considered keywords, as they are very common and may not help narrow your search. Most of the searches you do in library resources will use keywords, so choosing accurate ones from your research question will give you better results. For example, note the keywords in the following research question:

• What effects does preschool have on long-term academic success?

Using the highlighted keywords will help you locate information that is more closely related to your research question compared to less specific terms like “early education” or simply “success.”

Keywords

Note: You may only become aware of related words after you’ve run a couple of searches. As you review your search results, take note of any recurring terms that seem to be related to your topic. For example, you may notice a particular database includes more sources on “pre-K” rather than “preschool”. Using this information, you can update your query to retrieve more sources related to your research question.

It helps to brainstorm as many other keywords related to your topic as you can. There may be different keywords to describe your topic, and some library resources may use different terminology than what you think is the obvious choice. For example, using the keywords we identified in our research question (What effects does preschool have on long-term academic success?), let's brainstorm related words.

Brainstorm

This is an example of keyword indexing. A database relies on an index, or list of keywords, to organize the materials that it contains. Depending on the topic, field, or intended audience, the index may include different versions of common terms, like “preschool” and “pre-K” as well as highly technical terms. Think of scientific and medical databases which often use the scientific, Latin-based names to organize its sources.

In addition to a database’s index of keywords, a thesaurus can help you find synonyms for your keywords. Think about your research question: Are there different words or phrases that describe what you are looking for?

Thesaurus

Can you find the best keywords in these research questions?

Most likely, the library resource will parse your question and pull out the most important keywords. However, without additional clues as to what to include or exclude, a search tool may incorrectly highlight nonessential words like “how” or “long-term” as your intended search terms. If this is the case, you’ll get too many results which include the common words in your question, rather than your keywords.

Some library resources use natural language searching. You probably are familiar with this technique from using general search engines like Google. Type your keywords as you would speak them. For example, enter the following in your search box as-is:

Natural Language Searching

While natural language searching may be the easiest method to use, it generally is not the most accurate. To get more precise search results, you should try connecting terms using Boolean operators. They may be familiar to you from mathematics or logic.

Boolean Operators

AND is the most commonly used Boolean operator. It is used to narrow your search so that you get fewer results. When you use AND between two keywords, you only receive results that include both search terms, but they are not necessarily next to one another in sentences.

Boolean Operators: AND

The Boolean operator OR broadens your search, increasing the number of results you receive. When using OR, you see results that contain either one or both of your search terms. This can be useful when you need to search multiple variations or synonyms of a word.

Boolean Operators: Or

The Boolean operator NOT narrows your search, so you receive fewer results. The NOT operator is used to retrieve results that include only the first term and exclude the second term. This can be useful when one of your keywords has multiple meanings that are giving you irrelevant results.

Boolean Operators: Not

When searching for a phrase of two or more words, use quotation marks “ ” around the phrase. The results will include documents containing those words in that exact order, which can help the accuracy of your search. For example, using quotation marks around “early childhood education” will retrieve sources with that exact phrase in its title or body of the text. When you don't put the phrase in quotations, the search also will include instances where the words appear separately, which may be irrelevant.

Quotation Marks

Nesting is a technique where you combine the Boolean operators within parentheses ( ), like mathematical equations. This allows you to search for multiple variations of keywords, according to the functions of the operators. For example, you could search for the following:

Nesating

Database Searching

While every database is different, there are helpful tricks that can improve your search results in almost any database. When you run a basic search, the database will look for the terms that occur anywhere in an article. This is called full-text searching. Using this method, you’ll get many, often thousands, of results.

Another option is field searching. Every book and journal article in a database has its own record that consists of several parts, or fields, that can be searched individually. These fields include Title and Author. Using field searching will narrow your search results only to the field you select. As you can see, limiting the search for “therapy for phobia” to results with this term in the document title only, greatly reduces the number of relevant results. In this example, the title field is abbreviated as “ti” in the search field.

Field Searching

You can add on to your search to locate a source by a particular author using the abbreviation “au”. Don’t forget to include your search term (in this case, the name of the author) in parentheses following the abbreviated field name. This is useful when you are looking for a piece that you may have read, but can’t remember the complete title or the author’s full name.

Full-text searching usually will provide the largest number of results, though many may be irrelevant. A full-text search anywhere in the article for "teenagers depression" in this psychology database leads to more than 27,000 results, which includes everything from books, scholarly articles, and dissertations.

Quality vs. Quantity

Adjusting to a field search, we search for the same terms only in titles of articles and receive fewer than 20 results. While we don't get as many results using a title search, since the results we do receive are in the title, they are more likely to be relevant.

Databases typically assign several subjects to a given article. Depending on the database, these terms are arranged by topic such as age group, study stage, or source type. Using subject terms instead of keywords can improve your search, because you know you're using the right words to describe your topic. What if you don't know what subject term to use? Start by doing a keyword (or "anywhere") search. In the search results menu, you should see a list of subjects associated with your topic. You can use that word or phrase in a new search by clicking on the link.

Subject Searching

Alternatively, you can type the term in the advanced search tool and choose "subject" from the dropdown menu.

For example, if you were to try a keyword search for "multiple personality disorder" you’ll see that this database aligns the keyword with the “personality disorders” subject and additional related terms like “dissociative disorders.” Try clicking on the terms used to index the article to locate more sources that may be relevant to your topic.

Another way to find subject terms is to use the "Look Up Subjects" feature, if your database has one. Try searching for a general term such as "depression." You'll see a list of more specific terms that may offer you better results. Some databases do not have this feature, or it may not give you the results you're looking for. It's always important to try multiple techniques in research. Next, we'll look at using the database's thesaurus, which can be an effective tool for attaining a full list of subjects.

Look Up Subjects

Often, databases will have a "thesaurus" feature that can help improve your results. Thesauri can:

• Show you if a database uses a slightly different term to describe the same idea.
• Help you think of related terms you also might want to search with.

For example, a search for "Manic Depression" in the database PsycINFO reveals the alternate term "Bipolar Disorder."

Thesaurus

Searching for "teen* AND depress*" can capture more relevant results than "teenagers AND depression."

Sometimes you miss a result when searching because an article uses a slightly different version of a word in your search. For example, a search for "teenagers AND depression" would miss an article titled "Helping Depressed Teens." Truncation helps you avoid this problem by using symbols, also known as wildcards, to replace letters in words. Different databases use different wildcard symbols. Popular ones include $ and *.

Truncation & Wildcard

Another way to improve your search is by adding limits. Most databases will have a feature that allows you to limit your search by different factors. These include: date, location, full text, peer review, and source type. Depending on the database, you may see additional limiters like methodology, publication title, or language. Typically, you’ll find these limiter options in the Advanced Search tool or on the search results page. You may need to expand the search results menu to view all of the limiters available in the database.

Limiting Your search

See how using or not using limits affects your search results. First, imagine we conducted a search for "therapy for phobias" without using any limits. In this database, we receive over 13,000 results. Next, imagine we conducted our search again, this time using limits. We limit our results to articles that: 1) are peer reviewed, 2) were published in the last 12 months, and 3) study adults. This search yields 29 results. Conducting a search using limits usually leads to fewer results, but the results you do get will be more relevant to your specific research needs.

Using Limits