Choosing the correct statistical test
Questions to ask yourself:
1.
2.
3.
4.
What scale of measurement has been used?
Are you testing differences between groups or associations between variables?
Are the samples independent or related (same person tested twice or paired ppl)?
How many groups are involved?
Nominal data:
Nominal Data
Hypothesis of Difference
Hypothesis of Association
Independent Selection
Related selection
Any number of cells
Chi Square
McNemar Test
Coefficient of Contingency
Ordinal data:
Ordinal Data
Hypothesis of Difference
Hypothesis of Association
Independent Selection
Related selection
Spearman r
Two Groups
More than 2 group
Two groups
More than 2 groups
Mann-Whitney U
Kruskal-Wallis H Test
Wilcoxon T test
Friedman ANOVA by
ranks
Interval/ratio data:
Interval Data
Hypothesis of Difference
Independent Selection
Hypothesis of Association
Related selection
Two groups
More than 2 groups
Two Groups
2 or more groups
Two groups
2 or more groups
Pearson r
Multiple R
Independent t Test
One-way ANOVA
Paired t-test
Within-subjects ANOVA
With prediction
With prediction
Regression of Y on X
Multiple regression
More than 1 IV
Factorial ANOVA