Module Components

• Overview

Topics

• T-TESTS
• Mann-Whitney U and Wilcoxon Signed-Ranks Tests

NRSG 795: BIOSTATISTICS FOR EVIDENCE-BASED PRACTICE

Module 5: Significance Testing/Hypothesis Testing for Two Groups

Overview

In this module, the concepts of significance testing and hypothesis testing will be examined for testing differences in means of two groups. Both parametric tests (when the variable of interest is normally distributed in the population) and non-parametric tests (when the variable of interest is not normally distributed in the population) will be described.

In using parametric tests when the dependent variable is interval/ratio level, test assumptions must be assessed. Assumptions include: random sampling, independence of observations, normal distribution, and homogeneity of variance. Although procedures for testing mean differences are often considered “robust” to violation of assumptions, the assumptions should still be evaluated.

Objectives

At the conclusion of this module, the learner will be able to:

• Identify and test the assumptions of tests of mean differences for two groups
• Perform a mean differences analyses and interpret output

• Prepare text and tabular summaries that represent tests of mean differences for two groups
• Correctly interpret tests of mean differences for two groups in manuscripts particularly with regard to test assumptions, sample size, and generalizability of findings.

Directions

There are 2 subtopics, each with required videos assigned within the subtopics. Learning activities within the subtopics are designed to help you apply what you learned.