Sources like relics, artifacts, remains, documents, and witnesses are accurate when proven to be authentic and credible
The authenticity of a source increases the credibility of that source
A primary source is more reliable than a secondary one
The credibility of a source is increased if it is corroborated by independent sources
Sources would tend to be bias, especially to its provenance or to the one who made it or held its custody
If sources like witnesses or their testimonies do not have immediate interest or direct involvement to the event, they become more credible than those who have interest or direct involvement
If all independent sources agree to a certain event, then the event becomes usually acceptable or factual
Testimonies of witnesses are credible if the witnesses are mentally and emotionally fit at the time of the interview or declaration
The source that does not conform to its milieu is considered a fabricated source