Example 1:

Linda, the researcher, publishes a research study (primary research) in 2012 that is focused on parents monitoring of their children's cell phone usage. In her study, Linda surveyed 800 ninth graders in Latvia. Another researcher, Edgars, uses Linda’s research in his literature review (secondary research) published in 2020 and summarises his findings based on Linda’s research findings as well as other researchers’ findings from their studies.

Example 2:

A researcher wants to understand football match attendance and how to improve communication with spectators in a stadium. The researcher then drafts a theoretical question. S/he could gather data first-hand, but instead opts for optimising the research schedule and looks for ready-to-use data. The researcher finds an organisation that collects data about stadium attendance, including data of interest to the research. That dataset may come in handy, but it was not designed to answer the research question (Martins et al., 2018:2).

Example 3:

A team of researchers want to understand the influence of regional institutions in location choice of cross-border acquisitions (the purchase of a company or assets in another country). Whereas gathering data first-hand for dozens of countries is certainly possible (however long this may take), it is much easier to find world databases that gather at least a subset of the intended data and complement them with smaller national statistical databases (Martins et al., 2018:3).