Then the birder will look for specific characteristics that eliminate it from the original impression. If no eliminating characteristics are seen, then the identification stands. I suggest that beginning birders don't just accept the first call of a more experienced birder. Well, this is one of the characteristics that make the observation a Nashville Warbler. Don't expect your birding companions to identify a bird you saw by only a few characteristics.
Most experienced birders identify a bird by many impressions along with their expectations.
A birder learns quickly not to doubt a reported identification as rare birds tend to show up in unexpected places. I will now run through a few scenarios I use for identification. As many books have been written on bird identification this list is very limited but hopefully will provide a possible path that might lead to an identification. The bird is soaring, has broad wings and spread tail. Third, I look at the tail and note it is reddish in color with no barring.