Track each source's date, purpose, access to events, and scope. Distinguish disagreement about facts from disagreement about definitions. Absence from a partial record is not automatically proof that something never occurred.
Worked example
A bridge may open to pedestrians before opening to carts. Two accounts giving different opening dates could use different meanings of opening; further evidence is needed.
Fictional Practice Records
A permit authorizes bridge construction in March 1890. A diary says the writer walked across in June. A council notice announces cart access in August. The surviving work ledger is missing its June page. These are invented records, not quotations from an archive.