TEAS Ready🧩 Reading · Integration of Knowledge and Ideas · Lesson 5 of 5 · 5 min
Primary vs secondary sources and judging credibility
🗂️ Nurses read research, patient records and news reports every day. Knowing which source is first-hand and which one to trust is a skill the TEAS tests directly.
💡 Key idea
Primary sources are first-hand; secondary sources report on them; credibility depends on expertise, evidence, recency and bias.
🧠 The idea
A PRIMARY SOURCE is first-hand: created by someone who took part in or directly observed an event or study. Examples are a researcher's original study report, a diary, a patient's own account, an interview transcript, a photograph or raw data. A SECONDARY SOURCE describes, summarizes or interprets primary sources: a textbook, an encyclopedia entry, a news story about a study, or a review article. To judge CREDIBILITY, ask who wrote it and what their expertise is, whether they gain money or attention from a certain conclusion (bias), how recent it is, whether it cites evidence that can be checked, and whether other reliable sources agree. A credible source is not always primary, and a primary source can still be biased or mistaken. The best source for a question is the one most relevant, expert, current and free of conflicts of interest.
✏️ Worked example
A student wants to know whether a new vaccine trial succeeded. Choices: a blog post by a celebrity, a newspaper article summarizing the trial, the research team's published trial report, and an ad from the vaccine's maker. The published report is the primary source, written by the experts who ran the study and checkable by others. The article is secondary and fine for an overview. The ad has a clear conflict of interest, and the celebrity has no relevant expertise.
📌 Takeaways
- Primary = first-hand record; secondary = a report about it.
- Check expertise, evidence, recency and who gains from the claim.
- Primary does not automatically mean trustworthy.
📖 Terms in this lesson
Primary source: A firsthand, original record created at the time by someone involved; for example, a nurse's diary written during a hospital strike.
Secondary source: A work that describes, analyzes or summarizes primary sources; for example, a textbook chapter about the history of nursing.
Credibility: How trustworthy a source is, based on the author's expertise, evidence, date and purpose; for example, a current report from a medical research center is more credible than an anonymous post.
✅ Check yourself
Question 1 of 3
Which is a PRIMARY source about a nursing strike in 1990?
- A diary kept by a nurse who joined the strike
- A history textbook chapter on labor events
- A recent article reviewing books on the strike
- An encyclopedia entry on the strike
Show the answer and rationale
Answer: A
A diary written by a nurse who took part is a first-hand record, so it is primary. The textbook chapter, encyclopedia entry and review article all describe or interpret events after the fact, which makes them secondary.
Question 2 of 3
A website praising a sleep supplement is run by the company that sells it. What is the main credibility concern?
- The site has a conflict of interest.
- The site uses a lot of medical vocabulary.
- The site may be too recent.
- The site is a primary source.
Show the answer and rationale
Answer: A
The company profits if readers believe the supplement works, so it has a conflict of interest that may bias its claims. Being recent, being primary or using medical words are not by themselves reasons to doubt it.
Question 3 of 3
Which source would be MOST credible for current dosing guidance on a common medicine?
- A current drug reference written by pharmacists
- A friend's memory of what a doctor said
- A forum post from an anonymous user
- A fifteen-year-old pamphlet found in a drawer
Show the answer and rationale
Answer: A
A current reference written by pharmacists combines expertise and recency. The old pamphlet may be out of date, the anonymous post has no known expertise, and a friend's memory is second-hand and easy to get wrong.
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