Types of data collected. Primary data and Secondary data

Primary data: Here we generate our own data through our own data collection process. Thus we can assure the quality of such primary data. It was discussed yesterday.

Secondary data: When secondary data is used in data analysis, we are actually using data published from other sources. Here we use fish that has been fished by somebody else. So we cannot be sure of its quality and freshness. Especially in developing countries one cannot be sure of the quality of secondary data. So we use secondary data published from reliable sources.