No. 246 · Evidence · Statistics and Probability
Meta-Analysis
Many small, uncertain studies, pooled together, can give one clear answer.
In the Almanac
“The Cochrane logo”, 1993 · “Merck’s Vioxx”, 2004
Both stories in full, three ways to use it and where it misleads.
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Questions
What is Meta-Analysis?
A meta-analysis pools the results of many separate studies on the same question into one overall estimate. Small studies are noisy and often inconclusive alone, but combined they can reveal clear benefits or hidden risks years earlier than any single trial.
How do you use Meta-Analysis?
To use it, look past single headlines and seek reviews of the full body of evidence. Combine your own small experiments and gather many independent sources before big decisions. But remember the result is only as good as the studies that go into it.
When does Meta-Analysis matter?
Meta-Analysis is one of the 68 mental models for evidence, the situations where you ask: Is this really true? Within that, it belongs to “Testing a claim”, alongside False Negative, False Positive and Falsification.
What is an example of Meta-Analysis?
Two stories show it at work: The Cochrane logo (1993) and Merck’s Vioxx (2004). Both are told in full in The Mental Models Daily Almanac, which has two stories for each of its 365 models.
Which mental models are related to Meta-Analysis?
Systematic Review, Publication Bias and Central Limit Theorem. Meta-Analysis itself comes from statistics and probability.