Archive:Advanced ANOVA/One-way ANOVA: Difference between revisions
wikademia>Jtneill mNo edit summary |
wikademia>Jtneill |
||
| Line 11: | Line 11: | ||
# Establish [[hypothesis|hypothesis/hypotheses]] | # Establish [[hypothesis|hypothesis/hypotheses]] | ||
# Examine [[../Assumptions|assumptions]] | # Examine [[../Assumptions|assumptions]] | ||
# Examine descriptive statistics, particularly the four moments (''M'', ''SD'', [[Skewness]], [[Kurtosis]]) overall, and also for each group | # Examine [[descriptive statistics]], particularly the four moments (''M'', ''SD'', [[Skewness]], [[Kurtosis]]) overall, and also for each group | ||
# Examine graphs, e.g.,: | # Examine [[graphs]], e.g.,: | ||
#* Histograms | #* Histograms | ||
#* Normal probability plot | #* Normal probability plot | ||
| Line 20: | Line 20: | ||
# Calculate and interpret effect sizes | # Calculate and interpret effect sizes | ||
#* Eta-square (omnibus - equivalent to ''R''<sup>2</sup>) | #* Eta-square (omnibus - equivalent to ''R''<sup>2</sup>) | ||
#* Standardised mean effect size (difference b/w two means) | #* Standardised mean effect size (difference b/w two means) - e.g., [[Cohen's d]] | ||
==Visual ANOVA== | ==Visual ANOVA== | ||
Revision as of 12:41, 3 December 2008
Template:50%done This tutorial teaches understanding and use of one-way ANOVA as a statistical technique for testing mean differences on a single variable measured for three or more independent groups. Practical exercises are based on using SPSS. |
Introduction
- [[../Assessment/]]
General steps
- Establish hypothesis/hypotheses
- Examine [[../Assumptions|assumptions]]
- Examine descriptive statistics, particularly the four moments (M, SD, Skewness, Kurtosis) overall, and also for each group
- Examine graphs, e.g.,:
- Histograms
- Normal probability plot
- Error-bar graph
- Conduct inferential test (ANOVA) and interpret significance of F
- Conduct follow-up tests (planned contrasts or post-hoc tests) if F is significant
- Calculate and interpret effect sizes
- Eta-square (omnibus - equivalent to R2)
- Standardised mean effect size (difference b/w two means) - e.g., Cohen's d
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?
Data
See also
- Analysis of variance/Data analysis tutorial (3rd year tutorial)
- Analysis of variance (Wikipedia)
External links
- ANOVA (ucspace)