Confirm identity before comparing dates
Two people with the same name can make a false conflict. Compare place, spouse, children, occupation, address, witnesses and associates. If identity is not secure, separate the candidate profiles before deciding that one person changed age.
Build a conflict table
List the claimed date, record type, date created, informant if known, whether it is an original or derivative, exact wording and citation. Include family trees and recollections, but label them accurately rather than giving every row equal weight.
Consider distance from the event
A birth record created near the birth may have stronger date evidence than a death certificate completed decades later, but record type alone does not decide reliability. Ask who knew the information, why it was recorded and whether an image or only a transcription was viewed.
Look for calculation and calendar problems
An age in years may produce two possible birth years depending on whether the birthday had passed. Ages were rounded, misunderstood or intentionally changed. Dates may reflect civil versus church events, delayed registration, different calendars or transcription errors.
Seek independent evidence
Find records created for different purposes: civil registration, church register, census, military record, immigration file, marriage license, newspaper, gravestone or family Bible. Several online trees repeating one unsourced date are not independent evidence.
Write the reasoning, not just the winner
State the conclusion, strongest evidence, conflicts, rejected alternatives and what could change the answer. Use terms such as confirmed, supported, probable or unresolved. If the day remains uncertain, publish the year or range rather than a false exact date.
Common questions
Clear before you continue.
Which record is always most reliable?
None. Reliability depends on the specific information, informant, timing, purpose and whether you viewed the original or a derivative.
Should I average two birth years?
No. Averaging produces a date that may appear in no source. Explain the range and evaluate the evidence behind each value.
Can I leave two dates in my tree?
Yes, if the software allows alternate facts and source notes. Mark the preferred conclusion and explain why the conflict remains.
Sources and further reading
Wiserta summarizes these resources for practical family use. Repository rules and record availability can change; verify details with the holding institution.
A useful next step