How to Tell If a Study Is Reliable in Five Minutes

4 October 2026

A reliable study has enough participants studied in a sensible way, compares its result against something real, and reports findings that actually match its own data. You can check all of this in about five minutes, without any training in statistics or science. The checklist below works for health claims, psychology findings, nutrition advice, and almost anything else that gets reported as research.

Check who was studied

Start with the basics. Was this study done on people, animals, or cells in a dish. A finding in mice is not the same as a finding in humans, no matter how exciting the headline sounds. Cell studies and animal studies are useful early steps, but they need to be followed up in people before the result means much for your own life.

Then check how many people took part and whether they look like you. A study of twenty university students tells you little about how a drug works in elderly patients. A study of five thousand adults across several countries tells you more, but only if it actually measured the thing being claimed, not something loosely related to it.

Numbers alone do not guarantee quality. A huge badly designed study can still mislead you. What you are looking for is a sample that is large enough and varied enough for the question being asked, not just a large number for its own sake.

Look for a fair comparison

Good studies compare one group against another. If a new treatment is being tested, there should be a group that did not get it, or got a standard alternative instead. Without this comparison, you cannot tell whether people improved because of the treatment or because of something else entirely, including the simple passage of time.

Watch for studies that only describe one group with no comparison at all. A report that says fifty people took a supplement and felt better tells you almost nothing, because you do not know what would have happened to those same people without it.

The strongest comparisons involve randomly assigning people to groups, so that the two groups start out similar in every way except the thing being tested. If a study instead lets people choose their own group, differences between the groups can explain the result just as easily as the treatment can.

Follow the money

Check who paid for the study and who stands to benefit from a particular result. This information is usually in a short section near the end of a paper, often labelled funding or conflicts of interest. News articles rarely include it, so you may need to find the original paper.

Funding from a company that sells the product being studied is not automatic proof of bias, but it is a reason to read the methods more carefully. Look at whether the study was designed and analysed independently, and whether the result was published regardless of what it showed.

A useful habit is to ask who would be disappointed if this study found nothing. If the answer is a company, a political campaign, or an advocacy group with a fixed position, treat the result as one data point rather than a settled fact.

Compare the claim to the evidence

Headlines and press releases often say more than the study actually shows. A study that finds a small association in a narrow group can turn into a headline that sounds like a universal rule. Read past the headline to the actual result, usually described in the first paragraph or two of a news article, or the abstract of a paper.

Pay attention to the difference between something being linked to an outcome and something causing it. A study can show that two things tend to happen together without proving that one leads to the other. If the article never explains how the researchers ruled out other explanations, treat the causal claim with caution.

Also check the size of the effect, not just whether it was found. A result can be real but tiny, barely worth changing your behaviour over. Good reporting usually gives you some sense of scale. If it does not, that absence is itself useful information.

Check for replication

One study, however well designed, is rarely the final word. Science builds confidence through repetition, with different researchers testing the same idea in different places and getting similar answers. A single striking result is a starting point for more research, not a conclusion.

Look for phrases like previous studies have found, or this confirms earlier work, which suggest the finding sits within a wider pattern. If a result is described as the first study to show something, that is not a flaw, but it does mean the finding is less tested and more likely to be revised later.

Be especially cautious with results that feel surprising or that overturn something widely believed. These are the claims most likely to generate excited coverage, and also the ones most likely to not hold up once other researchers try to repeat them.

Run the checklist in order

Put these steps together and the five minutes looks like this. First, check who was studied and how many of them there were. Second, look for a comparison group, and work out what the result is actually being measured against. Third, find out who funded the work and whether that creates an obvious interest in a particular outcome.

Fourth, read the actual result rather than the headline, and notice whether the article talks about cause or only about a link. Fifth, see whether other studies have found something similar, or whether this is a lone result standing on its own.

No single answer on this list makes a study trustworthy or worthless by itself. What you are building is a rough picture. A study that does well on most of these points deserves more of your confidence than one that fails most of them, and that relative judgement is usually all you need to decide how much weight to give a claim.

Common questions

Does a study need a huge sample to be trustworthy?

Not always. The right sample size depends on the question, a study of a rare disease may only ever involve a few hundred patients worldwide. What matters more is whether the sample fits the question being asked and whether the comparison group is sound.

What should I do if a new study contradicts older research?

Treat it as a prompt to look for more evidence rather than a reason to switch your view immediately. Science often moves through disagreement before a clearer picture settles, so one contradicting result is interesting but not decisive on its own.

How do I actually find out who funded a study?

Search for the original paper rather than relying on a news summary, and look near the end for a section usually called funding, acknowledgements, or conflicts of interest. Many journals require this disclosure, so it is often there even when news coverage leaves it out.

Is a study automatically less reliable if a company funded it?

Not automatically, plenty of well designed, independently analysed studies are funded by companies with a stake in the result. The warning sign is not funding itself but a lack of independent oversight, or a pattern of only publishing favourable results.

Does publication in a famous journal guarantee a study is solid?

It raises the odds, since well known journals tend to have stricter review, but it is not a guarantee. High profile journals have published results that later failed to hold up, so the checklist still matters even when the source looks impressive.

Read next

• Preprints vs Peer Review: What Actually Changes

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• What Statistically Significant Really Means

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