P - Patient or Population
I - Intervention
C - Comparison (if any)
O - Outcome
*Shlonsky & Gibbs, 2004 call this COPES searching, Client-Oriented Practical Evidence Searching
A research study where data is collected by the investigators conducting the research. This can include carrying out a survey, coding specific behavior or doing an experiment.
A research study based on data which other investigators have collected. Using U.S. Census data, finding articles and systematic reviews from a library database are all examples of secondary research. Secondary research is much less expensive and time consuming than primary research. Much of social science research relies on secondary data gathered and compiled by others. ¹
¹ Lewis-Beck, Michael S. "Secondary Data." Encyclopedia of Social Science Research Methods. 2003. SAGE Publications. 27 May 2010. <http://www.sage-ereference.com/socialscience/Article_n898.html>.