ANOVA Flashcards
What is S^2 within?
The within-groups estimate of the population variance
What is S^2 between?
Between-groups estimate of the population variance
What is SStotal?
Total sum of squares
What is SSbetween?
Between-groups sum of squares
What is SSwithin?
Within-groups sum of squares
What is dftotal?
Total degrees of freedom
what is dfbetween?
Between-group degrees of freedom
Is dfbetween always on the numerator or denominator?
Numerator
What is dfwithin?
Within-groups degrees of freedom
Is dfwithin always on the numerator or denominator?
Denominator
How many IV’s are in a one way ANOVA?
One
Nominally scaled
Three or more levels
What do you assume about the populations in a one way ANOVA?
They’re normal, have equal variances and independent scores
How many dependent variables does a one way ANOVA have?
One
What scale of measurement does the DV have in a one way ANOVA?
Equal interval
Step one of one way ANOVA
Restate the question as a research and null hypothesis
What is the null hypothesis in a one way ANOVA?
Mew1 = mew2 = mew3
What is the research hypothesis for a one way ANOVA?
The population means differ in some way
- cannot be written in symbols
What is type 1 error in a one way ANOVA?
The probability of rejecting the null hypothesis when it is true
S^2 within in a one way ANOVA
Looks at variance within each sample to estimate population variance
S^2 between in one way ANOVA
Looks at variance between samples to estimate population
What happens in a one way ANOVA if there’s no treatment effect and the null is true?
S^2 within = S^2 between
What happens in a one way ANOVA if there’s a treatment effect and the null is false?
S^2 between > S^2 within
What is an F ratio in a one way ANOVA?
Comparison of the two population variances
What will the F ratio be when there’s no treatment effect and the null is true?
Close to 1