I am getting interesting reactions to the term, "authority." Because I am a classicist, "authoritative" means "correct," not necessarily because someone insists. Classics has a side to it that most people are unaware of. The field developed as a science before there were "soft" and "hard" sciences. Just science. In German, it is altertumswissenshaft -- the science of antiquity. This idea of authority for me is perfectly represented by a page from an Oxford Classical Text. Generations of scholars have come to consensus about what the "correct" letters should be, and at the bottom of the page there is the apparatus criticus where variant readings are noted along with the sources in which they are attested or the scholars who suggested them. It is a science and a humanity.
My working definition of authority, then, for this particular project, is this: the consensus of a group of committed researchers putting forth their best conclusions using the best information at hand at the time. This definition is subject to change, of course, as this committed researcher gathers more information over time and continues to refine his conclusions.