Archive:Advanced ANOVA/One-way ANOVA

This tutorial focuses on one-way ANOVA.

Introduction

• Unit outline (updated - to upload/link)
• [[../Assessment/]]

General steps

1. Establish hypothesis/hypotheses
2. Identify IV (categorical; between-subjects) and DV (at least interval)
3. Examine assumptions:
   • The data in each cell is normally distributed
   • Homogeneity of variance (the variance in each cell is similar)
   • Cells are independent
4. Create descriptive statistics
5. Possible graphs:
   • Bar graph
   • Box and whisker
   • Error-bar graph
6. Conduct inferential test and interpret significance
7. Conduct planned contrasts of post-hoc tests if F is significant
8. Interpret effect sizes (later in this tutorial)
   • Eta-square (omnibus - equivalent to R²)
   • Standardised mean effect size (difference b/w two means)

Visual ANOVA

• Understanding ANOVA Visually (may require viewing with Internet Explorer)
• Under what conditions would F be the smallest?
• Under what conditions would F be the largest?
• Now explore the same ideas with this more advanced Visualisation Tool for One-way and Two-way ANOVA Applet

Error bar graphs

• Use any dataset
• Conduct a one-way ANOVA and graphically present the means and confidence intervals using an Error Bar Graph - is this error bar chart consistent with the statistical results? Why? Why not?

See also

• Analysis of variance/Data analysis tutorial