How Biographies Are Researched

Start with a question, not a pile of facts

A biography is not a list of everything a person ever did. It starts with a question: what does this life explain? For a scientist, the question might be how the discovery happened; for a leader, how power was won and used. The question decides which facts matter and which sources to chase. A biographer who starts by collecting facts without a question ends up with a pile, not a book.

That is why two good biographies of the same person can look so different. They asked different questions, so they gathered different evidence and told different stories — and both can be honest. When you read a biography, ask first what question it is trying to answer.

Primary sources come first

The strongest evidence is primary: material created by the person or by people who were there — letters, diaries, notebooks, official records, photographs, interviews. Marie Curie's laboratory notebooks, for example, still show her working methods and her exposure to radiation; Albert Einstein's letters show his thinking changing year by year, in his own words.

Primary sources are not automatically true — a letter can lie, a diary can flatter, a memory can fail — but they are the closest a researcher can get to the event itself. Everything else is built on them.

Secondary sources fill the gaps

No life survives entirely in primary sources. Biographers also use secondary sources: other biographies, histories, scholarly articles and journalism written later by people who studied the evidence. These are useful for context — the politics of a decade, the state of a science — and for events the subject never wrote about.

The rule is to treat secondary sources as leads, not verdicts. A claim that appears in one modern book and nowhere else is a claim to check, not a fact to repeat. Good biographers follow the footnotes back to the primary source before they trust a striking detail.

When sources disagree, say so

Sources disagree often, and honest biography shows the disagreement instead of hiding it. Muhammad Ali Jinnah's birth date is a famous case: his earliest school records suggest 20 October 1875, while Jinnah himself maintained 25 December 1876 — the date Pakistan observes as a national holiday. Neither date can simply be deleted; the reader deserves to know both, and why each is claimed.

A biography that quietly picks one side has made an editorial decision without telling you. A careful one states both, weighs them, and lets you see the reasoning. That is the standard this site holds itself to.

Review before publication

Research is only half the job. Before a biography reaches readers it should be checked by someone who did not write it — a second pair of eyes looking for errors, unsupported claims and missing context. On this site every profile needs at least three independent sources and a second review before publication, and facts are labelled as verified, interpretation, disputed or unconfirmed. Unconfirmed claims are never published as fact. See our fact-checking methodology and sources policy for the full rules.

If a mistake slips through anyway, the honest response is a public correction, not a silent edit. That is why the site keeps a corrections policy and updates it in the open.

How to judge a biography you are reading

Four quick checks will tell you most of what you need to know. First, does it name its sources — and can you follow them? Second, does it admit uncertainty where the evidence is thin? Third, does it show both sides when the sources disagree? Fourth, was it reviewed by someone other than the author? A biography that passes all four is worth your trust; one that fails the first is worth very little, however well written it is.

Start with the profiles on this site's most famous scientists list and see the method in practice: every entry links to a full biography with its sources listed on the page.

Frequently asked questions

Sources and further reading

• Wikipedia — “Biography” (history of the genre, primary vs secondary material)
• Top Personalities — Fact-checking methodology
• Top Personalities — Sources policy

Further reading

• Fame vs Influence — What's the Difference? — Fame is being known. Influence is changing what happens next. They overlap — but not nearly as much as we assume.
• How to Evaluate Historical Sources — Six checks that separate a reliable source from a shaky one — who wrote it, when, why, and whether anyone else agrees.
• Understanding Historical Timelines — How to read a life in dates — what timelines show, what they hide, and how to spot a misleading one.