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English 277 Technical Writing for Engineering: Searching Databases Basics

Guide to the research process for the class.

Database Basics

This page introduces features available in the Engineering Village Compendex database. Many of these strategies and options are available in other databases but may look different based on the producer of the resource.  If you have questions about how to use any of the resources available on the engineering research guides, contact the librarian listed on the guide.

Engineering Research Guides

Note: On all of the Engineering Research Guides you will find the librarian's contact information and a mechanism for requesting an appointment (which can be in-person or virtual).

Database Strategies

Compendex Term Recommender

The "Auto Suggest" feature in Engineering Village Compendex suggests terms that retrieve the best results.  In the example here, a search for "photovoltaic cells" is a useful term.  The recommended term for "photovoltaic generators (solar)" is "solar cells."  Clicking on the recommended term (Solar cells) will identify all the items where that phrase is included in the record. 

To make the search even more relevant, search for the term as an "Ei controlled term" as shown below.  Terms recommended by the system are generally available as Ei controlled terms.  Records are only given Ei controlled terms if they are enough about that topic to warrant the term being applied.  In this example, photovoltaic cells in all fields retrieves 75,070 items whereas searched as an Ei controlled term finds 39,356 records.  Although the search finds fewer, the sources found will be more relevant.

Using Ei controlled terms



Use the keywords you identified build your search by creating a separate "set" for each concept.  The example below illustrates combining a variety of terms related to solar power and combining them together using "OR".  This step finds all the items that use these terms.  Then, do a new search using the terms identified for the other concept, for example parking structures.

Multiple terms for one concept

After creating both sets (or as many as you need for the concepts in your topic), combine the sets together with "AND" to create a final set that contains sources that discuss both concepts.  The numbered steps below illustrate how to combine sets in Compendex.  Start with the "Search History," then check the boxes for the sets you want to combine.  If you have conducted more than two searches, click on "Show all" at the bottom of the Search History box and select the sets to combine.

Combining search sets

In this example, the combined search results contain 378 sources that discuss solar energy on parking structures.

Now, look at the results to see if the sources are useful.


Examine more closely some of the sources that seem the most relevant to your search by clicking on the title of the article. A few of the important areas to look at are highlighted in the example record below. The terms used in the search are highlighted in yellow.

  • The citation is outlined in light blue. It includes the article title, authors, source (i.e., journal title), volume, page numbers and year are all very important to have for citing the source.
  • The abstract is outlined in red.  The abstract gives an overall summary of the contents of the resource so you can determine if it addresses what you need.
  • Ei controlled terms and Uncontrolled terms are outlined in dark blue.  Looking at the other terms applied to the source can provide additional terms that you might want to use in further searches to focus your results.  When searching for uncontrolled terms, use the "all fields" in the Quick Search box.

Full record areas of importance

Most databases include a variety of types of sources, sometimes for many years and possibly in languages other than English.  Further refine your search by using the limiters on the left side of the screen.

Refining options in CompendexLimiters can include:

  • Controlled vocabulary - allows adding in additional terms (think Ei controlled terms)
  • Document type - SDSU does not have easy access to very many conference proceedings, so it is often helpful to limit results to journals because these will be easier to access.
  • Language - a helpful limiter if you do not read other languages besides English.
  • Year - a useful limiter to focus on the most recent information available. 

Once you've chosen your limiters, click on the "Limit to" button to search again with your refinements.

As you look through your results, you'll need to identify whether the source is available to you through the library.  Click on the SFX button as illustrated below to find out options for access.

Results screen in Compendex

In these examples, SFX shows that SDSU does not subscribe to this journal, so to read this article you would need to request it through interlibrary loan.

SFX result of don't own

For the second item, SFX provides a direct link to the article.  Simply click on the "Full Text Online" link and the article should open in your browser.  When accessing resources from off-campus or to request an article through interlibrary loan, you will need to enter your SDSU user name and password (use the credentials you use to access MyState or your email).

SFX result with link to full text


  1. From the list of Research Guides above, identify the one that fits best with your engineering project.
  2. Open the Guide and choose one the the top databases listed on the Articles tab.
  3. Explore the database by searching with the keywords you identified previously.  Think about the following questions:
    1. What types of sources are included in this database?  Who appears to be the audience for these sources?
    2. Is full text of articles included or do you need to use the SFX or Find It @ SDSU button?
    3. What other keywords or subject words can you identify that will be helpful?
    4. How well do the limiters help you focus your results?
  4. Consider trying other databases listed on the guide.  What differences do you see?


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