Tests of significance

Two questions arise about any hypothetical relationship between two variables:

1. what is the probability that the relationship exists;
2. if it does, how strong is the relationship

There are two types of tools that are used to address these questions: the first is addressed by tests for statistical significance; and the second is addressed by Measures of Association.

Steps in Testing for Statistical Significance:

1) State the Research Hypothesis
2) State the Null Hypothesis
3) Select a probability of error level (alpha level)
4) Select and compute the test for statistical significance 

Chi Square TestàFor nominal and ordinal data, Chi Square is used as a test for statistical significance.

T-Testsà are tests for statistical significance that are used with interval and ratio data. 

NOIR: Nom/Ordà chi sq, Int/ratioàT-test

5) Interpret the resultsà

                    I.            the hypothesis

                  II.            the test statistic used and its value

                III.            the degrees of freedom

                IV.            the value for alpha (p-value)