Evaluating a Health Claim Found Through Search
Marcus searches for information about a supplement that a friend says 'cures' a chronic condition. The top three results are: (1) a sponsored link to an online shop selling the supplement, (2) a blog post with no author name, dated 2011, containing testimonials and a 'buy now' button, and (3) a page on a national health service website summarising the current evidence, with a named medical reviewer and a review date of three months ago. Marcus only reads result (2), because it is written in a friendly tone and matches what his friend told him. He is about to spend money on a six-month supply.
1. Assess the credibility of each of the three results and explain which Marcus should rely on.
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| Result | Assessment |
|---|---|
| (1) Sponsored shop link | Commercial intent - the site profits from the claim. Advertising placement is not an endorsement of accuracy. |
| (2) Anonymous blog, 2011 | No author or credentials, no cited evidence, out of date by over a decade, testimonials are anecdotal, and a purchase button signals commercial motive. Weak on every criterion. |
| (3) National health service page | Named reviewer, recent review date, institutional accountability, and it summarises evidence rather than selling. Strongest source. |
Marcus should rely on (3). Note the confirmation bias at work: he chose (2) because it agreed with what he already believed, not because it was better evidence.
2. List the specific checks Marcus should apply to any health-related web page before trusting it, and explain why 'it matches what I was told' is not a valid check.
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Checks to apply:
- Authorship - is a named person with relevant qualifications responsible for the content?
- Currency - is there a publication or review date, and is it recent?
- Evidence - are claims backed by cited research rather than testimonials?
- Purpose/bias - is the site selling something or funded by someone who benefits from the claim?
- Accountability - does the organisation have a reputation to protect (e.g. a public health body)?
- Corroboration - do independent, reputable sources say the same thing?
Why agreement is not a check: a claim agreeing with what you were already told only shows the source repeats your prior belief - it is circular. Two people can share the same unverified claim. Agreement measures comfort, not accuracy.