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Library Resource Guide for Clinical Researchers

Database Tips & Tricks

Searching in databases can be daunting, but the Library is here to help. This page contains information on how to search in databases effectively. Please always feel free to reach out to your liaison librarian for assistance. 

Tips & Tricks for Searching in Library Databases

  • Document your search strategy
    • Write down everything you do. Documenting your search is important so you know where you've been and where you're going.
  • Search line-by-line
    • Instead of combining all your topics into one line and searching, try searching one concept at a time, then combining those concepts with the advanced search function of a database.
  • Citation Chasing
    • Examine the references of a resource that you've already found to be helpful in your project. You may find more resources, or more keywords, in these article lists.
  • Cited Reference Searching
    • Find out who has cited the resource that you've already found to be helpful in your project. You may find more current resources and/or keywords in these articles.

Keywords and Subject Headings 

Keyword searching is using natural language to search in databases. You will find your keywords from your research question.

Subject Headings are predefined controlled vocabulary words used to describe the content of each item in a database. You will find these in the database which you are searching. Not every database has subject headings readily available. Please feel free to reach out to your liaison librarian for assistance with subject headings.

Keywords Subject Headings
  • natural language words describing your topic - good to start with
  • pre-defined "controlled vocabulary" words used to describe the content of each item (book, journal article) in a database
  • more flexible to search by - can combine together in many ways
  • less flexible to search by - need to know the exact controlled vocabulary term
  • database looks for keywords anywhere in the record - not necessarily connected together
  • database looks for subjects only in the subject heading or descriptor field, where the most relevant words appear
  • may yield too many or too few results
  • if too many results - also uses subheadings to focus on one aspect of the broader subject
  • may yield many irrelevant results
  • results usually very relevant to the topic

Source: MIT Libraries 

Boolean Operators: AND, OR, NOT

The three basic Boolean operators are AND, OR, and NOT.  You can use Boolean operators to focus your search and produce more productive results. Below you can find an infographic on how Boolean operators work.

Boolean Venn Diagrams

Search Logic: Nesting

Databases are machines that require precise language to operate how you want. Use searching logic in conjunction with Boolean operators to build the search that you really mean. Databases recognize AND as the primary operator, and will connect concepts together with AND unless you tell them otherwise. Combine AND with OR operators in a search with parentheses correctly for the best search strategy.

Nesting Venn diagrams

 

The above graphic illustrates how databases interpret nesting. The first search string employs nesting properly, so the database reads this search as:

  1. The database first searches for music therapy
  2. The database then searches for breastfeeding OR nursing together
  3. The database combines these two concepts and only pulls articles that contain music therapy AND (breastfeeding OR nursing)

The second search string does not employ nesting, so the database reads this search as:

  1. The database first searches for music therapy
  2. The database then searches for music therapy AND breastfeeding
  3. The database then adds nursing to the end of the search with or, reading the search like (music therapy AND breastfeeding) OR nursing

PubMed Searching Tutorials

PubMed has an advanced search builder function that allows researchers expanded opportunities for searching in PubMed. Check out the video below for more information on how to use it.

Medical Subject Headings, or MeSH, is the NLM controlled vocabulary thesaurus used for indexing articles for PubMed. Check out the video below for more information on how MeSH works.