Learning Objectives
- Define the term research database.
- Differentiate between a subject and keyword search.
- Build a search using Boolean operators (AND, OR, NOT).
- Understand how to use truncation, nesting, phrase searching, and field-specific searching.
What is a Research Database?
A database is a searchable collection of information. Most research databases are searchable collections of journal, magazine, and newspaper articles. Each database contains thousands of articles published in many different journals, allowing you find relevant articles faster than you would by searching individual journals.
Some databases provide the full text of articles. Others provide abstracts, or summaries, only.
Searching a Library database is different from searching the Internet.
| Google, Wikipedia | Academic Search Complete, JSTOR, OVID, ScienceDirect |
| Anyone can publish and anyone does. Difficult to verify credentials. Results are not always scholarly. | Authority/credentials are guaranteed. Most articles are scholarly and peer-reviewed. |
| Thousands. Duplicates are not filtered out. Many are not scholarly. | Hundreds or fewer. Duplicates are filtered out. You can limit to full text. |
| Lots of "noise" because there are no subject headings assigned. Information can be biased, untrue, or irrelevant. | Databases focus on specific subjects. Offer fewer but more relevant results. Results are from scholarly publishers and authors. |
| Can limit by document type (pdf, doc) and source (gov, org, com) | Can limit by date, language, format, peer reviewed status, full text availability, and more. |
| Information from the Internet is unstable. It can disappear at any time. Researchers will often be asked to pay a fee to access journal articles. (Note: These articles are available to you via the Library as part of your tuition.) | Databases are a collection of articles that have appeared in journals. This makes their status more stable than the Internet. The information is paid for by subscription to be offered as part of a student’s tuition. |
Selecting a Database
Selecting the best research databases for your topic is an important step. You need to locate databases that cover your topic within the date range you need.
Find all of our databases on the Academic Databases page (from the Library website, click "Databases" in the menu bar). Use the "Subjects" dropdown menu to select your discipline. Skim through the list of databases to learn:
- Subjects covered
- Types of publications covered (e.g., journal articles, books, etc.)
- Dates covered
Keyword Searching
Keyword searches are similar to Google searches in that the database looks for your search terms wherever they may be on a page. Keyword searches search all available fields (e.g., Title, Author, Abstract, etc.) for the keyword.
Example:
In the example record below, you can see the keywords "video games" and "aggressive behavior" in bold in every field where they appear, including the Title, Subject Terms, and Abstract fields.
Subject Searching
Unlike keyword searches, subject searches only return results that include your search term in the subject headings field.
Many databases use a controlled vocabulary, which is a list of standardized subject headings used to index content. You can usually find the database's controlled vocabulary in a section called subject terms or the thesaurus. Use this tool to determine which word or phrase is the one used by the database for a specific concept. For example, since "adolescents" and "teenagers" mean roughly the same thing, a database may choose to index all articles on this topic under "teenagers." That way, a subject search for "teenagers" will also return articles about "adolescents."
Example:
In the database Academic Search Complete, we clicked "Subject Terms" in the blue menu bar. We then browsed for the term "adolescents." The search revealed that the preferred term in this database is "TEENAGERS."
Keyword vs. Subject Searching
Databases have different interfaces and use different subject terms, but most provide both keyword and subject searching. Let's take a closer look at the differences between these two search options.
| Natural language. A good way to start your search. | Predefined controlled vocabulary usually found in the database's thesaurus. |
| More flexible. You can combine terms in any number of ways. | Less flexible. You must know the exact controlled vocabulary term or phrase. |
| Database looks for keywords anywhere in the record (title, author name, subject headings, etc.) | Database looks for subjects only in the subject heading or descriptor field, where the most relevant words appear. |
| Often yield many irrelevant results. | Results are usually very relevant to the topic |
Watch the video below to learn more.
Source: Wayne State University Libraries Instruction. “Keyword vs. Subject Searching.” Online video clip. YouTube. YouTube, 9 January 2014. Web. 12 May 2017.
Phrase Searching
Place quotation marks around a phrase to search for that exact phrase. Most databases support phrase searching.
Example: A search for "United Nations" (with the quotation marks) will return only results where the two words appear together as a phrase.
For a quick demo, watch the video below.
Source: "Tips and Tricks: Phrase Searching" by North Carolina State University Libraries, licensed under a CC BY-NC-SA 3.0 US License.
Boolean Operators
When you want to combine search terms, you will need to use the Boolean operators, or connectors. This is best done using the advanced search mode. There are three main Boolean operators: AND, OR, and NOT.
AND
Use AND to retrieve articles that mention both terms somewhere in the article. The use of AND generally will retrieve fewer but more focused results.
Example: Childhood obesity AND exercise
OR
Use OR between two terms to retrieve articles that mention either term. The use of OR generally will retrieve a larger set of results.The OR operator is useful when searching with terms that are synonyms or convey the same concept.
Example: Cloning OR genetics OR reproduction
NOT
Use NOT to exclude terms. The use of NOT allows you to remove search results containing a specific term. The use of NOT generally will retrieve fewer but more relevant results.
Example: Eating disorders NOT anorexia
Effective use of Boolean operators is essential to sophisticated research. Watch the video below to learn more about Boolean searching.
Source: fuliboutreach. “Boolean Operators.” Online video clip. YouTube. YouTube, 30 September 2012. Web. 4 May 2017.
Field Specific Searching
A good technique for focusing a database search is to limit your search to a specific field. Do a field-specific search when you are looking for:
- articles in a particular journal
- items published in a particular year or years
- particular keywords in the title
- items written in English only
Example: Search for "Eating Disorders" as a keyword; search for "Gupta" in the Author field; search "Secondary Eating Disorder" in the Title field.
Truncation
Truncation is a search technique that allows you to search for all variants of a root word at the same time. Enter the root word followed by the truncation symbol. Many databases use the asterisk (*) for truncation. Others use the question mark (?). Check the Help page for the database you're using to determine which symbol to use for truncation.
Example: The search termplagiar* will return results that include terms:
- plagiarism
- plagiarize
- plagiarizing
- plagiarized
- plagiarizer
- plagiarizers
- plagiarist
Broadening Your Search
Keep in mind that if you're looking for an all-in-one source that addresses your topic perfectly, you might need to change your approach. Watch this short video to learn what to do when you can't find enough resources on your topic.
Source: “One Perfect Source?” by North Carolina State University Libraries, licensed under a CC BY-NC-SA 3.0 US License.