When an outlet says “six White House officials” or “seven Department of Justice officials,” it’s providing a level of precision that makes me more likely to trust the story. This does not necessarily mean that the story is correct. But it does suggest it was thoroughly reported.
A recent New York Times story, for example, described something top White House adviser Jared Kushner was saying in private meetings, according to “six West Wing aides.” Six people are less likely to be wrong than one — and this also indicates that the reporter was cautious and diligent enough to seek confirmation with more than one person. CNN’s recently retracted report that Congress was looking into a Russian investment firm with potential ties to people in Trumpworld, meanwhile, cited only a single anonymous source.
And, obviously, if multiple reputable news organizations or reporters report out and confirm the same story (not just link to another outlet’s reporting), that’s a reason to assume it is accurate. Conversely, if another major publication is casting doubts on a story you read that quotes lots of unnamed sources, that should heighten your skepticism. For example, In the Iraq War era, even as The New York Times and other outlets often echoed the Bush administration’s assertion that Iraq possessed large numbers of weapons of mass destruction, there were publications like McClatchy that were more skeptical of the government’s claims.