If we want our genealogical research to stand the test of time, we need to understand which sources are most reliable. Any document is subject to human error, but every time it is copied, more possibility for error is introduced. That’s why the most reliable sources are those that are created at the time of an event. In addition, if the person who is giving the information to the record keeper is an eye witness to the event, there is more possibility for accuracy.
Think, for example, who the informants are for a wedding certificate or parish record. The bride and groom each give their pertinent information to the person performing the wedding. In addition to their names, they may be required to tell their ages, residence, occupations, and parents’ names and occupations. It is possible a bride or groom may give false information purposely, but most often, information on a marriage record is provided by someone who knows the facts. The marriage date on a marriage record is very likely to be the correct one. A death record, on the other hand, may have an informant who didn’t know for sure the decedent’s age or names of his parents, etc.
When we are deciding which records are most reliable, we consider when and by whom the record was made. There are three categories to consider when analyzing sources:
- Type of record – is it an original, a derivative such as a transcription, or a compiled narrative?
- Type of information in the record – does it directly or indirectly answer the question?
- Type of informant – was the informant an eye witness to the event? Then the informant was considered a primary informant. Did the informant only know what happened because someone told him? Then the informant was a secondary informant. Was the informant unknown? Then the informant was undetermined.
Obviously, the most reliable records would give direct evidence on an original record by a primary informant. If no direct evidence can be found, two or three records providing supportive indirect evidence would also be reliable — preferably provided by an original record with a primary informant. When you go further down the line of reliability, you end up with a compiled record such as an unsourced online family tree with an unknown informant. These unsourced records can be valuable as clues, but should always be backed up by reliable source documents.
Part of the Genealogical Proof Standard includes using reliable evidence and conducting a reasonably exhaustive search for that evidence.