Who wrote it, when, and why — how to evaluate a source without dismissing it as biased, and why bias makes a source more useful, not less.
La respuesta corta
Evaluating a historical source means asking who produced it, when, for whom and why. Reliability is not a property a source simply has or lacks — it depends on the question being asked, and a biased source is often the best evidence for what people believed.
El método, paso a paso
1
Check the provenance first
author · date · audience · type of source
Provenance is everything surrounding the source rather than its content. Reading it before the source itself shapes how you interpret every line, which is why examiners provide it and expect it to be used.
2
Establish the purpose
why was this produced, and for whom?
A private diary, a public speech and a government poster have different purposes and therefore different relationships with the truth. Purpose predicts what a source will emphasise and what it will leave out.
3
Distinguish content from inference
what it says vs what it lets you conclude
Content is directly stated; inference is what you can reasonably deduce, including from what is absent. Both are examined, and questions asking what a source 'suggests' want inference rather than quotation.
4
Judge reliability against a specific question
reliable for what?
A propaganda poster is unreliable evidence for what conditions were actually like and excellent evidence for what a government wanted people to believe. Naming what the source is reliable for is what earns the marks.
5
Set the source in its context
what else was happening when this was made?
Own knowledge is required alongside the source. A source produced during a war, a famine or an election means something different from the same words produced in calm conditions, and answers without context stay shallow.
Bias is not a reason to dismiss a source
The weakest answers in source questions say a source is biased and stop, as though bias settled the matter. Every source is produced by someone with a viewpoint, so noting bias distinguishes nothing.
The useful move is to ask what the bias reveals. A source exaggerating an enemy's cruelty tells you little about the enemy and a great deal about the propaganda aims of whoever produced it — which is frequently the more interesting historical question.
Provenance: author, date, audience, type
Purpose predicts emphasis and omission
Content is stated; inference is deduced
Reliability is always relative to a question
Context from own knowledge is required
Primary and secondary sources
A primary source was produced at the time by someone connected to the events. A secondary source was produced later by someone interpreting them. Neither is automatically more reliable — a primary account can be mistaken or deceitful, and a secondary one can draw on far more evidence than any individual witness had.
The distinction matters for what a source can be used for. Primary sources give access to contemporary perspective; secondary sources give access to accumulated analysis, and good answers use both.
Comparing sources
Where two sources agree, the claim is strengthened — particularly if they had no reason to coordinate. Where they disagree, the disagreement itself is evidence, and explaining why two people saw the same event differently is often the point of the question.
Answers should compare rather than describe each source in turn. A question asking how far two sources agree wants the comparison foregrounded, not two separate summaries with a sentence at the end.
How we teach source analysis
We ban the sentence 'this source is biased' unless it is followed by what the bias reveals. It is the single most common way students waste a paragraph, and removing it forces the analysis that earns marks.
We also require the provenance to be read and annotated before the source content. Students who read the extract first form an impression and then fit the provenance around it, which is the wrong order.
Preguntas frecuentes
What is provenance in a historical source?
Everything about where the source came from — who wrote it, when, for what audience and in what form. It should be read before the content, because it shapes how every line is interpreted.
Does bias make a source unreliable?
Not in itself. Every source has a viewpoint, so noting bias distinguishes nothing. The useful question is what the bias reveals — a propaganda poster is excellent evidence for what a government wanted people to believe.
What is the difference between primary and secondary sources?
A primary source was created at the time by someone connected to events; a secondary source was produced later by someone interpreting them. Neither is automatically more reliable — they answer different questions.
How do you judge whether a source is reliable?
Always against a specific question. Ask 'reliable for what?' — a source may be poor evidence for what happened and excellent evidence for what people at the time believed or were told.
What do you do when two sources disagree?
Treat the disagreement as evidence. Explaining why two people saw the same event differently — their position, purpose and audience — is usually the point of the question rather than deciding who was right.
