ABSTRACT
Most of the tests covered in this book (e.g., t-tests and analysis of variance) are
parametric
tests in that they depend considerably on population characteristics, or parameters, for their use. The t-test, for instance, uses the sample’s mean and standard deviation statistics to estimate the values of the population parameters. Parametric tests also assume that the scores being analyzed come from populations that are
normally distributed
and have
equal variances.