27 March 2014
The quality of "proof" depends upon the quality of the research process, the quality of the sources used, and the quality of the documentation that keeps track of those sources.
It depends upon the quality of the information in those sources, the quality of the interpretation of that information, the quality of the analysis and correlation of everything that has been found, and the quality of the reasoning that goes into the final conclusion.
We've come a long way since those secondary and undergrad classes when we picked up the idea that "proof" meant having a source to cite!