Statistical Powers, P Values And Confidence Levels.

Confirming cause and effect relationships can be hampered by noise. If an effect occurs some percentage of the time in the presence of a potential cause, then the percentage is referred to as the statistical power. If an effect occurs some percentage of the time in the absence of a potential cause, then that percentage is referred to as the p value. 100 minus the p value is referred to as the confidence level. Note that the confidence level is the percentage of the time in the absense of a potential cause that an effect does not occur.