A document can be genuine and still provide a partial account. An administrative report, a private letter and a newspaper story answer different questions. Before quoting any of them, establish what kind of record you have and what it was created to do.
Begin with a source note
Write down the creator, date, intended audience, repository and reference number. Distinguish the date of the event from the date of the record. A recollection written decades later belongs to a different evidentiary context from a note made that afternoon. Neither is automatically useless; each needs an appropriate question.
A scan is also a version. Check whether it includes every page, attachments and the reverse of handwritten sheets. An excerpt may omit a qualification that changes the meaning of the passage. If the original cannot be consulted, state which copy you used.
Separate observation from interpretation
Use three columns in your notes: what the source explicitly says, what other records support, and what remains your interpretation. Suppose a report lists people as absent. That entry alone does not establish where they went or why. Resist filling the gap with the explanation that fits your preferred story.
Ask how the creator acquired the information. An eyewitness description, a copied message and an unverified report can appear on the same page. Identify the difference before treating the whole document as testimony.
Compare records without flattening differences
Find a second source created for another purpose. Repeated wording may indicate copying rather than independent corroboration. Differences in names, dates or numbers deserve a note, not silent harmonization. Keep Korean names as they appear in the source and record alternative romanizations separately.
A useful stopping point
Your final note should explain the narrow claim the document supports and the question it leaves open. This keeps a small discovery from becoming a sweeping conclusion. A finding aid is a good place to understand the surrounding collection before moving to individual records.
Starting reference: National Archives: selected Korea records in State Department files. This guide introduces a collection; it does not replace examination of the records themselves.