Primary source

It refers to the source that originated the data. One of the fundamental rules of using secondary data is to use the primary source of a secondary data. There are two main reasons for this rule. First and foremost, the researcher the researcher needs to search for general evidence of quality. The primary source will typically be the only source that describes the process of collection and analysis. Thus, it is the only source by which this judgement can be made. Second, a primary source is usually more accurate and complete than a secondary source.