Mathématiques · Glossaire
What is P-Value?
Définition rapide
The probability of observing results at least as extreme as those observed, assuming the null hypothesis is true.
Explication complète
A p-value is the probability, under a specified statistical model (the null hypothesis), of obtaining a result equal to or more extreme than what was actually observed. A p-value of 0.03 means: if there is no real effect, there is a 3% chance of seeing data this extreme by random variation alone. The conventional threshold is p < 0.05 to declare "statistically significant." P-values do NOT measure the probability that the hypothesis is true, nor the size of an effect. They are widely misunderstood. Replication and effect size matter at least as much. The American Statistical Association has published warnings about p-value misuse.
Calculatrices liées
Calculators that use or explain P-Value.
Termes liés
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Last reviewed: June 15, 2026 • Category: Mathématiques