Experienced researchers often combine secondary data with primary data in the following situations:
A.
The research requires data for a regional or international comparison.
B.
The research requires data for a temporal/historical comparison.
C.
The research primarily relies on secondary data, but part of the data is missing or outdated.
D.
The research primarily relies on secondary data, but you would like to make an additional argument, which requires the support of primary data.
E.
The research primarily relies on primary data, but you may cite secondary data as the background of your research.