General principles

1. From the known to the unknown

Move from yourself to your parents, grandparents, great-grandparents, and confirm every step with a document. Do not look for a great-grandfather in the 19th century before you have established his children and where they lived. A "family memory" entry is fine as a hint, but not as a fact.

2. One source is not proof

Consider a fact established when it is confirmed by at least two independent sources: for example, a metric marriage record and a confession list with the same family. Two copies of one book (parish and consistory) are one source, not two.

3. Look for the whole family, not only the direct line

Having found an ancestor, look for all of his children, brothers and sisters, and also godparents, witnesses and guarantors. Many documents of the direct ancestor have not survived, while the documents of a brother or a godfather contain the information you need. Godparenthood and neighbourhood almost always point to relatives.

4. Do not rely on the surname

• Surnames were written in different ways: Cyrillic before and after the reforms, Polish, Latin, German (Wasyl and Василь, -czuk and -чук). Search all forms.
• Women were recorded under both the maiden and the husband's surname.
• There were many namesakes in one village. The same name and surname does not mean the same person: compare age, parents, wife, place.
• A nickname (a street surname) could replace the surname.

5. Absence of a record proves nothing

The book may not have survived, the record may have been entered in another parish, or the person lived in another village. Say "not found in these books for these years", not "did not exist".

6. Record the source at once

For every fact: archive, fond, inventory, file, folio (with verso), date of viewing, link to the scan. Without this a fact cannot be checked. The call number format is in the section archives. Write names and dates as they appear in the document; add your own normalized form separately.

7. Do not trust other people's trees

Other people's trees (on FamilySearch, Geni, Rodovid and others) are hints: they contain many copies of one mistake. Check every link against a document.

8. Age in documents is approximate

In confession lists and revisions age is often "by eye". Allow a discrepancy of 2–3 years and compare with the metric record.

9. Rules for AI agents

• Do not invent records, call numbers or links. If you did not find it, say so.
• Separate "found in Predok", "found in another open source (with a link)" and "assumption".
• For every conclusion name what it is based on and what could refute it.
• A person in Predok is a mention in one source; one human may have several records. Establish identity by names, dates, places and relatives, and explain it.
• Do not put living people into public answers and proposals unless they appear in an open source with a link.

Typical mistakes