What are the limitations on using primary sources?

such as eyewitness accounts, may be too close to the subject, lacking a critical distance. Others, such as interviews, surveys, and experiments, are time consuming to prepare, administer, and analyze.

  Primary sources can enrich and inform a research paper or project; they offer a unique perspective on an event, situation or person. These sources created during or very near in time to an event, provide unfiltered, first-hand descriptions that are absent from purely secondary and other sources.

the exodus of these people from constantinople contributed to the revival of greek and roman studies, which led to the development of the renaissance in humanism and science. byzantine emigrants also brought to western europe the better preserved and accumulated knowledge of their own greek civilization