Microbiology & Bacteriology

What are Primary, Secondary, and Tertiary Sources in Biology Research?

Biological information exists in different formats including: articles, books, and data. Sources can be primary, secondary, or tertiary. Authors of primary sources analyze data. Secondary and tertiary sources interpret and summarize other sources. Primary sources are often the most up-to-date, but can be difficult to read and understand. Secondary and tertiary sources are often easier to understand, but have undergone additional interpretation. 

Primary Sources

Original research, evidence, and analysis

Examples: Research articles, Patents, Research data, Lab notes, Conference presentations, Clinical trials, Original models

 

 

 

 

Secondary Sources

Summaries, evaluations, or interpretations of others' research

Examples: Review articles, Book reviews, Annotated bibliographies

 

 

 

 

 

Tertiary Sources

Collections and summaries of primary and secondary sources

Examples: Reference books, Dictionaries, Encyclopedias

 

 

Search tips for databases and the catalog

  1. Think about what you want to know
    The first step to successfully searching is having a mindset of inquiry. Design research questions when you develop your hypothesis, design your experiment, and explain your results. 
    Example: How does salinity affect rates of photosynthesis in Arabidopsis plants? 
     
  2. Gather a little background info and adjust the question as needed
    Go ahead, Google it. Or look in the library Reference section. 
     
  3. Narrow the question down to the main concepts and variables
    Example: How does salinity affect rates of photosynthesis in Arabidopsis plants? 
    salinity photosynthesis Arabidopsis
  4. Explore synonyms for your search terms.
    Examples: Salinity: Salt concentration, salt level. 
    Arabidopsis plant: A. thaliana

     
  5. Plan a search with Boolean operators and modifiers: 
    Symbol Example Description 
    AND (cats) AND (dogs) Adds search terms to the search, will limit the results to only articles that contain both terms. AND is usually implied, but can be used with parentheses and OR to make the search more precise.
    OR (Arabidopsis OR "A. thaliana") Expands the search, a good way to add synonyms or binomial names to search terms. This example will return any article with either the word "Arabidopsis" or A. thaliana.
    NOT Ash NOT tree Excludes articles that have the term. This will return results with the word "ash" but not if the results also contain the word "tree."
    * bio* Signifies a truncation symbol. Will yield articles with the prefix submitted and any ending, such as: 
    biology, biological, biome, biometrics, biography, biotic, etc.
    " " "breast cancer" Searches the exact phrase found in the quotes. This search will yield articles with "breast cancer," but NOT articles that only contain the word breast, or the word cancer, or contain the words separately such as cancer of the breast
    Example: (salinity OR salt) AND (photosynthesis) AND (Arabidposis OR "A. thaliana") 
     
  6. Enter your search in the library ESearch tool or a library database.
     
  7. Filter and sort your results
    Try the limiters (usually on the left side of the results pages) or sort the results by most cited, or newest. 
     
  8. Read titles and abstracts to get an idea of source content. 
     
  9. Find the full text and read the sources.
     
  10. Look up the citations in the sources you find for more potential sources. 
     
  11. Repeat these steps as you focus your research topic and RE-SEARCH!

Librarian

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Kelly Getz
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