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Research Guides

ENGR/HCDE 231: Introduction to Technical Writing - Fall 2018: Find Articles: How to Search

Database Search Techniques


The first and most common search technique is Keyword searching.  Keyword searches use natural language, or the words you naturally think of as the main terms for a topic.

After thinking about keywords ask yourself if they have any synonymous or related terms.  Adding synonymous or related terms terms will help you find more potentially useful results.  

Let's say I was interested in writing my memo on the effect of global warming on coast flooding. Right way, I would pick out the keywords global warming and coastal flooding.Climate change is a synonym of global warming and sea level rise is a direct cause of global warming related costal flooding. Instead of two search terms, there are now four:  global warming, sea level, coastal flooding, and climate change. 

Searching by keyword lets you create very flexible searches, however using it solely leads to an added risk of too few, too many, or irrelevant results.  Once you have some results, read some of the article abstracts and note some of the other terms or keywords used in those articles and use them to create new searches to see if you can find more focused articles.


One way of narrowing down and pinpointing more accurate results is to enclose terms that you want searched together in a specified order in quotation marks. This "phrase search" will tell that database that you are searching for one specific term and not two separated but related terms.

Global warming, sea level, coastal flooding, and climate change are all phrases. It would be better to search for them as "global warming", "sea level", "coastal flooding", or"climate change" .

Boolean Operators

AND and OR and NOT are called Boolean Operators. Using them allows you to construct a more specific and efficient search which then will bring you more focused results. Want to know more about using Boolean Operators? 

Use AND to reduce the number of items found:

Unless you specify otherwise, most databases will assume the Boolean AND connector, which means that all words must be present for a particular record to be listed in the search results, but not necessarily as an exact phrase. In other words climate change should get the same results as climate and change. But "climate change" will be more focused and find (fewer) results than the other searches, but they will all include that phrase.

Use OR to combine synonymous or alternate terms and thus increase the number of items found:

It helps to think of synonyms for your keywords and combine them with an 'OR'-- for example: "flood control" AND (dams OR levees OR dikes).  To narrow your search, think of more specific terms for your keywords-- for example, "flood control AND artificial levees".

With just your imagination and well-chosen search terms, you can create complex, but very powerful, searches, using both AND and OR in a single search.

Note the use of parentheses to group the terms connected by OR:

("global warming" or "climate change") and "sea level" finds only those items that have either the phrase global warming or the phrase climate change as well as the phrase sea level.

("global warming" or "climate change") and ("sea level" or "coastal flooding") finds those items that have at least one phrase from each group. Kind of a “mix and match” deal.

Truncation and Wildcard

Truncation broadens searches to variations on word endings.  If your keyword has multiple tenses and endings use truncation to increase the number of relevant results.  

Enter the root word and put the truncation symbol at the end of the root word to truncate your search.  Note that truncation symbols vary from database to database. Commonly used truncation symbols include: *,!,?, or #.

Articles on the topic of coastal flooding might use flood or floods instead of the gerund form flooding. To make sure the all forms of the keyword are search for use truncation.

For example: ("global warming" or "climate change") and ("sea level" or "coastal flood!") 

Similarly to truncation, Wildcards are used in cases where a word can be spelled multiple ways.

Most frequently this is because of international differences in written English.

thes!s = thesis or these
vapo?r = vapor or vapour

Subject Search

While keyword searches allow you to create your own search terms, subject searches use a controlled vocabulary, or indexed terms which have been applied to the documents in a database. 

Subject searches are much more ridged than keyword searches, because the database will only look for subject terms in subject heading or descriptor metadata fields of in the document's record. However, the results of this search will be extremely targeted to your topic. 

Another way of doing a subject search is through the subject headings. Most databases have an index of subject headings which link directly to all the articles classified with under that subject. 

In Academic Search Complete, the most appropriate subject headings would be Climate change and Absolute sea level change:

(DE "CLIMATE change")  AND  (DE "ABSOLUTE sea level change")

Frequently Used Databases