What are the differences between secondary and primary data collection?

Secondary data are available from two sources - internal and external. Internal secondary data may be drawn from company records and internal databases the company uses to store accounting, operations, or customer information. External secondary data are available from private research companies, government agencies, publications, and other Internet-based resources, databases, and reports. Primary data are collected by the company to answer a specific research question/issue. Primary data can be collected from qualitative methods such as focus groups, depth interviews, ethnographic research, and observation research. Primary data can also be collected by quantitative methods such as surveys and experiments.