Definitions for "TYPE II ERROR"
See BETA RISK.
The researcher's data-based decision that the null hypothesis is true when it is really false.  While this incorrect conclusion could be the result of bad luck as in the case of a Type I Error, a more worrisome possibility is that the experiment had low power.
If the null hypothesis is accepted when it is wrong, this results in a false negative result.
Keywords:  isn, mistake, saying, difference, based
A mistake based on saying there isn’t a difference when there is.
Keywords:  lane, steps
STEPS LANE
Keywords:  uniform, distribution
Uniform Distribution
When a survey finds that a result is not significant, though in fact it is.