Two records can give two different birth years for the same person. Which one should you believe? Learning to weigh up sources is the skill that separates a reliable family tree from a pile of guesses.
Ask four simple questions
Whenever you find a new piece of information, pause and ask:
- Who created this record? A registrar, a clergy member, a relative, a stranger?
- When was it created? At the time of the event, or years later?
- How did they know? Were they there, or were they told by someone else?
- Why was it made? Legal records, personal letters and newspaper stories all have different purposes.
The answers tell you how much weight to give each fact.
Original records and copies
An original record is the first version, created at or close to the time of an event. A birth register entry written a few days after a birth is a good example.
A derivative record is anything copied from an original: transcriptions, abstracts, printed indexes and online database entries. Derivatives are extremely useful for finding things, but each time information is copied there is a chance of error. Whenever you can, go back and view the original.
First-hand and second-hand information
A single document can mix reliable and less reliable details. A death certificate, for instance, records the date of death from someone who was probably present, which is first-hand. The same certificate may give a birth date supplied by a grieving relative from memory, which is second-hand and more likely to be wrong.
Tip: Ages on records are often approximate. When searching, look a few years either side of the expected birth year.
When sources disagree
Conflicts are normal. When two records disagree:
- Note both versions in your tree rather than quietly choosing one.
- Consider which source was created closest to the event, by someone with direct knowledge.
- Look for a third, independent record to break the tie.
- Write a short note explaining your conclusion, so others can follow your reasoning.
A word about online family trees
Shared online trees can be wonderful for finding leads and distant cousins. They can also repeat the same mistake hundreds of times. Treat any fact from another person's tree as a clue, and look for the record behind it before adding it to your own.
Building a strong conclusion
The most dependable facts in your tree will be supported by several independent sources that agree with each other. If a birth date appears consistently on a baptism record, a census return and a marriage record, you can be confident in it. If it rests on a single later account, mark it as uncertain until you find more.