A type II error is an error in hypothesis testing that occurs when a false null hypothesis is not rejected.
Type II Error
See also
Null Hypothesis, Sensitivity, Specificity, Statistical Test, Type I ErrorExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Type II Error." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/TypeIIError.html