the probability that an observed outcome of an experiment or trial is due to chance alone. In general, a result of a clinical trial is considered statistically significant if there is a less than 5% probability that the difference observed would occur by chance alone if the treatments being compared were equally effective (e.g., a p-value of less than .05).
STATISTICAL SIGNIFICANCE
Meaning of STATISTICAL SIGNIFICANCE in English
AIDS English Glossary. Английский словарь СПИДа. 2012