Evaluating Sources

Relevance: does the source answer your question?

A trustworthy source is not automatically relevant. A report about public transport in large cities may be reliable but only partly useful if your question concerns transport in rural areas.

Start by asking what information you actually need.

Credibility: what impression does the source give?

Credibility concerns whether the source appears worthy of trust. Useful clues include who is responsible for it, whether claims are supported, whether important details are transparent and whether the presentation gives reasons to be cautious.

A professional design can contribute to an impression of credibility, but appearance alone is never enough.

Reliability: what happens when you investigate?

Reliability requires checking rather than relying on first impressions.

Ask whether evidence can be traced, whether methods are described, whether important claims agree with stronger independent sources and whether the material has been corrected or challenged.

Usefulness depends on purpose

At a more advanced level, the question is not only 'Can I trust this source?' but 'What can I responsibly use it for?'

A personal interview may be weak evidence for how an entire population thinks, but valuable evidence for one person's experience. A national dataset may show broad patterns but reveal little about individual experiences.

Look for limits, not perfection

No source answers every question. Strong evaluation identifies both value and limitation.

Useful categories include author or organisation, evidence, method, date, purpose, scope, audience and possible interests.

Question

Does remote work improve employees' wellbeing?

Source A

A large national survey reports average levels of job satisfaction among remote and office-based workers.

Strength: broad sample and useful for identifying patterns.

Limitation: a survey can show an association without proving that remote work caused the difference.

Source B

A detailed interview describes one employee's experience of isolation while working from home.

Strength: gives depth and helps explain how isolation can be experienced.

Limitation: one person's experience cannot represent all workers.

Evaluation

Both sources can be useful, but for different purposes. The survey is more useful for broad patterns; the interview is more useful for illustrating an individual experience. Neither should be treated as complete proof on its own.

1. Define the question or purpose for which you need the source.
2. Check who created the source and in what context.
3. Identify the evidence, data or reasoning behind the main claims.
4. Check the date and whether the information is current enough for your purpose.
5. Compare important claims with other relevant sources.
6. Consider scope: who, where and what does the evidence actually describe?
7. Identify possible limitations, interests or missing perspectives.
8. Decide what the source is useful for and what it cannot support.

Mistake: 'It is a .org website, so it is reliable.'

Better: Investigate the organisation, evidence and purpose rather than trusting a domain ending.

Mistake: Rejecting a source because it has a perspective.

Better: Identify the perspective and evaluate how it affects the source's claims and usefulness.

Mistake: Treating one personal story as evidence about everyone.

Better: Use it for the individual experience it documents and combine it with broader evidence when making broader claims.

Mistake: Asking only whether a source is true or false.

Better: Evaluate specific claims, evidence, limitations and usefulness for your purpose.

You are investigating national voting patterns. Which source is most useful for estimating how common a view is?

• A. One detailed interview with a voter.
• B. A transparent national survey with a large, clearly described sample.
• C. An anonymous comment with no evidence.
• D. A fictional political drama.

Answer: B. A well-described national survey is better suited to estimating broad patterns, although you should still examine its method and sample.

• Relevance asks whether the source helps answer your question.
• Credibility concerns the impression of trustworthiness; reliability requires investigation.
• A source can be useful for one purpose and unsuitable for another.
• Evaluate evidence, scope, date, origin and limitations.
• Corroborate important claims rather than relying on one source.
• Strong source evaluation explains both what a source can support and what it cannot.