Signs test. Signs test compares two medians using the direction of the values with respect to the mean and binomial probability.
Power and sample size. Power and sample size are two related concepts, which have to do with the ability to detect the studied effect.
Standardization. Standardization is described, which consists of subtracting the mean from a value and dividing it by its standard deviation.
Dispersion measures. Dispersion measures such as variance and standard deviation are described, as well as their relationship with the confidence intervals.
Null hypothesis. The null hypothesis is the center of the hypothesis testing, which seeks to be able to reject it when statistical significance is reached.