ABSTRACT
Parametric statistical procedures allow you to draw inferences about populations based on samples of those populations. To make these inferences, you must be able to make certain assumptions about the shape of the distributions of the population samples. Section 6.1 Review of Basic Hypothesis Testing The Null Hypothesis
In hypothesis testing, we create two hypotheses that are mutually exclusive (i.e., both cannot be true at the same time) and all inclusive (i.e., one of them must be true). We refer to those two hypotheses as the null hypothesis and the alternative hypothesis. The null hypothesis generally states that any difference we observe is caused by random error. The alternative hypothesis generally states that any difference we observe is caused by a systematic difference between groups. Type I and Type II Errors
All hypothesis testing attempts to draw conclusions about the real world based on the results of a test (a statistical test in this case). There are four possible combinations of results (see the figure shown to the right).
