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IEE 594: Industrial Engineering Graduate Seminar

Introduction to the ASU Library and literature searching.

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Precision vs Recall

There are two criteria by which a successful search can be judged: 

  • precision - is what I found exactly what I need?

  • recall - have I found everything that I need?

Precision and recall are inversely proportional - if you require high precision then you will have low recall but if you require high recall you will have low precision. 

A literature review requires high recall and that requires different search strategy than a high precision search. 

Do you know what you're looking for?

Can you describe your information need  using one simple sentence or 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 : the population, product, process, problem, or predicament
  • I : the intervention, improvement or issue of interest for P
  • C : what you'll compare I to (ex. a different intervention/improvement/issue or the current standard of operation)
  • O : the outcome (the results of the comparison of I and C)


For a compressor cascade (P), what is the influence of free stream turbulence (I) on air flow (O)?   

Can molecular modeling (I) be more cost effective (O) than lump modeling (C) for heavy oil refining (P)? 

Does solar-power (I) produce enough energy (O) for running residential air-conditioning in desert climates (P)?

Search Strategy

Searching within a resource is always a multi-part process:


A. Start with a P AND I search

  • If you retrieve too many items, narrow the search by restricting the words to the title field (not every database allows this)
  • Look for articles that are very close or exactly what you want - examine each one for the controlled vocabulary (subjects and descriptors) that the database assigned to them; also look to see if you can find synonyms
  • Look for articles that are not as closely related but still have parts of interest; again, examine each article for synonyms and for the controlled vocabulary


B. Expand the P AND I search to include synonyms

  • Redo your search, this time including the synonyms you discovered above
  • For "single box" search engines do several simple searches employing only one or two synonyms at a time; do not put all the synonyms for all the concepts into one search as this will confuse the engine's relevancy algorithm. 


C. Search using the database's controlled vocabulary for P AND I 

  • In some databases, the controlled vocabulary may be called the thesaurus, subjects or descriptors.
  • Some databases, such as Google Scholar and Library One Search do not use controlled vocabulary, so you'll not be able to to do this type of search.  In this databases, you can use controlled vocabulary from the other databases in your keyword/synonym searches.  


D. Where do the C (comparison) and O (outcome) come into the search strategy?

  • If the results sets you get using just the two, P and I, concepts are just too large to work with,  AND in the O as another concept in the search.  Don't forget to find synonyms for this concept, too.
  • As you read the items you found, remember the C (comparison) and O (outcome) - this will help you decide which articles you can discard and which you should keep. 


E. For the most important documents you found, use citation searching to find even more:

  • Go backwards in time by finding the references cited in the document
  • Go forwards in time by finding the articles that cite this document (using Scopus and Google Scholar)


Continue on to the next section "Where to Look"

Return to the top of this page "Search Stategy"

Go back to the previous section "Your Tool Box"

The ASU Library acknowledges the twenty-three Native Nations that have inhabited this land for centuries. Arizona State University's four campuses are located in the Salt River Valley on ancestral territories of Indigenous peoples, including the Akimel O’odham (Pima) and Pee Posh (Maricopa) Indian Communities, whose care and keeping of these lands allows us to be here today. ASU Library acknowledges the sovereignty of these nations and seeks to foster an environment of success and possibility for Native American students and patrons. We are advocates for the incorporation of Indigenous knowledge systems and research methodologies within contemporary library practice. ASU Library welcomes members of the Akimel O’odham and Pee Posh, and all Native nations to the Library.