Research

How to evaluate sources

Q: What’s the difference between primary and secondary sources?

A primary source is original or first-hand (data, a diary, an experiment, an artwork). A secondary source interprets or analyses primary ones (a review article, a textbook). Tertiary sources, like encyclopedias, summarise both.

Q: Is Wikipedia a reliable source?

It’s a great starting point to understand a topic and find references, but it’s tertiary — cite the primary and scholarly sources it points to instead.

Good papers are built on good sources. Here’s a fast way to judge whether a source is worth citing.

A five-point checklist

Currency — is it recent enough for your topic?
Relevance — does it actually address your question, at the right depth?
Authority — who wrote it, and what’s their expertise? Who published it?
Accuracy — are claims supported by evidence you can check?
Purpose — is it meant to inform, or to sell or persuade?

Primary, secondary, tertiary

A primary source is first-hand (raw data, a letter, an experiment). A secondary source analyses primary ones (a journal review, a textbook). A tertiary source summarises the field (an encyclopedia). Strong papers lean on primary and peer-reviewed secondary sources.

Where the Study search fits

The Study search deliberately returns results only from trusted, ad-free educational sources, so you start from solid ground. Use it to orient yourself, then follow the references to primary and scholarly work — and cite those.

Frequently asked questions

What makes a source credible?

Check who wrote it and their expertise, whether it’s current, whether claims are backed by evidence, and whether it’s trying to inform rather than sell. A quick checklist is currency, relevance, authority, accuracy and purpose.

What’s the difference between primary and secondary sources?

A primary source is original or first-hand (data, a diary, an experiment, an artwork). A secondary source interprets or analyses primary ones (a review article, a textbook). Tertiary sources, like encyclopedias, summarise both.

Are scholarly sources always better?

For most academic work, peer-reviewed scholarly sources carry the most weight, but a reputable news outlet or government report can be exactly right depending on your question.

Is Wikipedia a reliable source?

It’s a great starting point to understand a topic and find references, but it’s tertiary — cite the primary and scholarly sources it points to instead.

These guides explain the current editions in plain language and are a study aid, not official style manuals. For exact rules and edge cases, check your assignment brief and the official APA, MLA or Chicago guidance — and when in doubt, ask your instructor.