Say you find a marriage record for a Samuel Carter in the right county and close to the right time. It matches the name of your ancestor, so it seems to have answered the question. And then you see another Samuel Carter on a census return for that same area, roughly the same age but married to a different woman. Each looks like a possible candidate. At this point, genealogy becomes less about finding names and more about comparing evidence.
A name is just one clue to identification, and it was often not recorded accurately in the past. Scribes made mistakes, families called each other by nicknames, immigrants anglicized their names, and indexes introduced transcription errors. Even a rare full name does not guarantee a unique person. Before you attribute a record to your ancestor, compare the age, location, occupation, spouse, children, parents, and any other people mentioned in the document. You will almost always get the right answer by combining several pieces of evidence, not by relying on one seemingly perfect match.
Choose a person from your tree you are unsure about, and draw two columns on a sheet of paper. In the left column, list only the facts you already know about this person: birth year, known places of residence, spouse, children, occupation, and religion if you have proof. On the right, copy the same information from the record you are testing. Note what matches, what does not, and what is missing. Do not try to account for any discrepancies yet. This simple exercise often highlights conflicting information before it can be ignored.
Some differences should not be taken too seriously. Ages vary from year to year, jobs are sometimes listed differently, and places of origin may be recorded generally in one record and specifically in another. More important discrepancies include a spouse with an incorrect first name, children who lived in different places in the same year, or two houses occupied in the same year. When you encounter uncertainties, treat all date information as broad categories, and be careful not to bend every inconsistency until the record fits perfectly.
Other individuals may also reveal more information than the ancestor’s own name. People named as marriage witnesses might be siblings. A neighbor on one census might turn out to be a relative in the next. A will might mention sons and daughters by names that match known members of the family. Research those people in your notes and check where they appear together. If you keep seeing groups of people together, you are likely on the right track in sorting out one Samuel Carter from another.
Location matters too. Two documents may contain the same place name but describe different jurisdictions, or a border change could place the same household in a new county without anyone having moved. Examine maps, local histories, church records, and surrounding communities. A ten-mile separation may mean very little in a sparsely populated region, but could be a big deal when two men share the same name and both are documented in the same year.
Do not throw away a potentially good record because it does not match up right now. Make a note of the source, state why it might apply, and label it as an open question. One day a birth record, a newspaper clipping, a cemetery headstone, or a family oral history might fill in the gap. Keep searching, and pay attention to when names alone stop looking like a match, and when houses, neighborhoods, jobs, and family members start pointing to the same individual.