Mechanical & Aerospace Engineering

This page focuses on how to do an in-depth literature review for a dissertation, thesis, grant application or lengthy term paper in electrical engineering.  

• For a more general description of what an in-depth literature review is and how it looks, see our guide on "Literature Reviews and Annotated Bibliographies" created by Ed Oetting, history and political science librarian.
  
  
• For lower-level engineering undergraduate students who are doing a short term paper, the "How to Research a Topic" page on the "Engineerng Basics" guide may be more applicable.

Gather Your Tools

Library Account
Is your library account clear of fines?   If not, you may not be allowed to check out more books nor renew books you already have.  All library notices are sent via email to your "asu.edu" address; if you prefer to receive email at a different address make sure you have forwarded your asu.edu correctly.  Also, make sure that your spam filter allows the library email to come through. 

Illiad (Interlibrary Loan) Account 
If you don't already have an ILLiad account, please register for one.  Interlibrary loan services will get you material not available at the ASU Library and also scan or deliver materials from the libraries on the other ASU campuses.

Determine the Project's Scope.

Do you know what you are looking for?  Can you describe your project using one simple sentence or can you phrase the project as a question?  Without a clear idea of the project, you may not be able to determine which are the best resources to search, what terminology should be used in those resources, and if the results are appropriate and sufficient.    

If you're having difficulty getting your project described succinctly, try using a PICO chart to identify the concepts involved:

• P is the popluation, problem, predicament or process
• I is the intervention or improvement
• C is what you'll compare your intervention/improvment to, and
• O is the outcome (or results of the comparison of I and C) 

For example: 

Your client, the owner of a nuclear power generating facility, has had several less than optimal safety inspections recently.  The inspectors have singled out operator error as a major concern and have required changes in employee training.  But is more training the solution?  The employees complain that the plant's poorly designed control room hampers their ability to respond to non-standard situations.  Could a redesign improve performance and decrease the occurance of unsafe events?   Your client wants more than just your opinion, he wants to see the data to back it up.   So, what can you find in the literature?

Here's one way that the PICO chart could be filled out:     

• P = nuclear power safety 
• I = human factors engineering
• C = additional training; little or no human factors engineering used 
• O = accident rate or safety inspection comparison

And here are examples of possible search statements:  

• I am looking for ways that human factors engineering can improve safety in the nuclear power industry.
• Is additional training or employing human factors engineering the better method for reducing safety violations in a nuclear power plant? 

Your research will always start with a "P AND I" search; those are the most important pieces of the puzzle.  However, once you have the results from that search, you'll need to know where you want to go with those results; that's when the C and O concepts need to be considered.  

 Also, don't forget --- determine if your project has limits.  For example:

• Are you reviewing the literature only within a specific time frame?
• Are you looking at English-language material only?
• Are you considering research from just the United States or worldwide?
• Are there types of material you won't be covering (trade magazines, patents, technical reports, etc.)?  

Create the Search Strategy

Take the simple sentence or question that describes what you are looking for.  What are the concepts in the sentence? Are there synonyms that describe the same concept?   If you filled out a PICO chart, concentrate on the P (problem) and the I (intervention) for the concept chart.  

Concept Chart:

Concept 1:  _______  OR _______  OR _______ 


AND


Concept 2:  _______  OR  _______  OR  _______ 


AND


Concept 3: _______  OR _______  OR  _______ 

 



Example:  

I am looking for ways that human factors engineering can improve safety in the nuclear power industry. 

Concept 1:  nuclear power   OR _nuclear industry_____ 


AND


Concept 2: _safety___  OR _accident prevention____ 


AND


Concept 3: _human factors engineering___   

What resources you'll use for your literature review depends on what types of materials you want to find.  

• Background Information
  The more you know about a topic, the better you'll be able to research it.  You'll be familiar with the terminology, understand the underlining science/technology and be aware of the issues in the field. Most importantly, you'll be able to understand what you've retrieved from your search.  But no matter how much you know before hand you'll likely run across terms and concepts with which you're unfamiliar.    Materials such as encyclopedias, dictionaries and handbooks will not only help you learn about the basics of your topic before you begin your search but they'll also help you understand the terminology used in the documents you found from your literature review.   
  
  You'll find these types of resources listed on the Dictionaries and Handbooks pages on this guide.
  
  
• Books
  The large size of books (usually 100-500 pages) allows a topic to be studied braodly, covering many different issues.  Conversely, the large size also allows for a specific aspect of the topic to be covered in great detail.  Because of the time it takes to publish, sci-tech books generally do not contain the most current information.
  
  To find print and online books from both the ASU Library as well as in other libraries, see the Books page on this guide.
  
  
• Conference Papers
  Scientists and engineers frequently present new findings at conferences before these findings are written up in journal articles or books.  Not every conference, however, publishes it proceedings.  In some cases, conferences publish only a few of the papers presented but not all.  
  
  Many resources that help you find journal articles, may also be used to find conference papers, see the Articles page on this guide.
  
  
• Journal and Trade Magazine Articles
  Articles in journals (also called magazines) are short, usually 5-20 pages in length and cover a specific finding, experiment or project.  Articles in scholary journals are usually written by academics or professional scientists/engineers and are aimed at others at the same level.   Articles in trade journals/magazines are written by the journal staff and report on industry news suchs as sales, mergers, prices, etc.  
  
  To find journal and trade magazine articles, use the resources listed on the Articles page on this guide. 
  
  
• Patents
  Patents are grants from governments that gives the inventor certain rights of manufacture.  Patents provide a wealth of information for how a technology is being advanced and by which companies.  It is frequently stated that 80% of the information in patents never appears elsewhere in the literature. 
  
  
• To identify patents granted in the U.S. and internationally see the "Searching for Patents" guide.
  
  
• To see statistical information for U.S. patents by technology class see the US Patent and Trademark's website.
  
  
• Technical Reports
  Technical reports are part of the "gray literature";  gray literature refers to documents that are not published commercially, hence they are difficult to both identify and find.  Technical reports focus on a specific experiment or research project and are meant to convey the results of the experiment or project back to the funding organization.  In the United States, common sources of technical reports are the government agencies that sponsor research projects.  Reports generated within a private corporation and funded soley by that corporation are seldom ever available to anyone outside of the company. 
  
     
  
  To find technical reports, use the resources listed on the Technical Reports page on this guide.     

Search, Read, Refine and Repeat

Now it's time to apply your search strategy in the resources you've decided to use.

1. Use the Advanced Search feature (or whatever search is set up with the 3 lines of boxes) and enter your search strategy just as you recorded in your search strategy chart.  Don't forget to set your limits.  
   
   If the resource only provides a single search box, rearrange your chart from vertical into horizontal so that the search statement looks like this:  
   
   (Concept#1 OR synonym) AND (Concept#2 OR synonym) AND (Concept#3 OR synonym)
   
   Example:
   (nuclear power OR nuclear industry) AND (safety OR accident prevention) AND (human factors engineering)
   
   
2. Examine the results to find the most appropriate items.  Keep your one-sentence project description (and/or your PICO chart) in mind to help you stay on track.
   
   
3. Export the records/citations you want to keep into a citation manager.
   
   
4. If there are subjects (may also be called subject headings, index terms, descriptors or controlled vocabulary) assigned to each item, make sure that those also transferred into a citation manager.  If not, add them manually.
   
   
5. Get the full text of the items 
   
   
6. Read the full text of the items and look at the subjects assigned to the item and consider:
   
   
• Do I have to change (narrow) my topic to something more specific because I'm finding way too much? 
• Do I have to change (broaden) my topic because I can't find enough about it? 
• Is there additional terminology for my topic/concepts that I hadn't included in my original search?
  
  
7. Redo your search strategy according to what you found in step #6 and rerun the search in the resources again.
   
   
8. You may need to repeat this cycle several times before you are able to identify the best terminology to use in each resource. 

Saved Searches, Alerts and Feeds

If there will be several months in between when you search the literature and when you turn in the paper, consider setting up alerts and feeds so that you are notified should new items about your topic appear.   How you set up an alert or feed will vary.  In most cases you'll be required to set up a personal account or profile with the journal or database --- there is no charge for this but you will have to identify yourself and provide an email address.  

For instructions on setting up alerts and feeds, see the "Keep Current" page.