primary/secondary data

• primary data 


  • Information that the researcher has collected firsthand for a specific purpose e.g. data from an experiment or observation
• evaluation of primary data 


  • more certainty on how valid it is, researcher themselves knows the strengths/ weaknesses of their own research.
  • likely to be scientifically gathered for the stated aim of the study. This means they are more credible.
  • New research and ideas can be discovered through primary data, as it may not have been explored before.
  • Expensive to obtain because each researcher or research team has to start from the beginning of a study and follow the whole study through
  • Time consuming,
  • Maybe biased due to the researcher wanting to find certain results.
• secondary data 


  • when the researcher uses information collected by others (often to answer other questions) e.g. the work of other psychologists or government statistics
• evaluation of secondary data 


  • Doesn’t take long to collect as the research has already been carried out.
  • Can gather lots of data in a short space of time.
  • Can help to build an idea about what most research is presenting in certain areas
  • Might not be relevant to what you are researching. This can lead to spending lots of time trawling through journals and research papers.
  • Data can be over complicated and may be more difficult to understand. This is because the research has been written by someone else.
  • Sometimes the data can be out of date (lacks temporal validity)