Can anyone tell me how accurate, on average, the data in the old census listings was? I ask, because, while looking up some people in the online 1880 census, I have found several cases where the ages given for these people varies wildly from the ages given elsewhere for them. (In one case, if the age given for one woman in the 1880 census was correct, she would have married at the age of about 13!) I'm not sure if this is from transcription errors when the 1880 census was put on the Internet, or if the old census records themselves were just plain unreliable. What do the more experienced researchers among you think?