score:8
Historians treat gossip (or, in French, "rumeur", and I understand your question in this way) in two ways:
1) as something to debunk. Unsubstantied facts that need (apparently, again and again) to be put to rest.
2) as a social fact. If someone or a lot of people or a crowd believe in gossip it's not the truth of the gossip that is important but its role in motivating agents to act. The Bastille was attacked to liberate the prisoners. There were 7.
Upvote:3
Unless the event is contemporary, gossip never comes out of a vacuum. It always has a source of some kind that is relating it. In those cases, the historian considers the track record and perspective of whoever it is relating the gossip, or the newspaper in which it appeared.
Additionally, there are two major ways to verify any information, including gossip:
(1) Is it consistent with other known or supposed independent facts? In the same way that you might question a group of criminals separately to see if they all tell the same story, a historian examines different independent pieces of evidence to see if they are consistent. Obviously, each piece must be independent from the other.
(2) Is something missing? An effective way to discredit a piece of spurious misinformation is to see if something is missing. For example, once I read a sensational chain email claiming that someone was putting AIDS-tainted needles in coin returns. Obviously it was false, because if it had been true, newspapers would have been reporting it. Also, the email conspicuously lacked any verifiable information: there was no place given, no dates, no hospitals or doctors cited, no police department mentioned; there was a complete lack of verifiable data. When an item lacks verifiable details and no reputable source is repeating the fact, that is usually strong evidence that it is misinformation.