3: independent 1-way ANOVA Flashcards
why don’t we use t-tests for tests with 1 Iv & >2 levels?
increased chance of Type 1 error
how do you calculate the error rate for a family of comparisons
=1-(% change of error (eg .05))^no.of comparisons
f ratio formula
variance between IV levels/ variance within IV levels
what is the difference between an F & t ratio
F is for ANOVA and t is for a t-test
which statistic should we report fi the homogenity of variance has been violated (levene’s is significant)
welch F statistic (put (Welch) after p value)
how do you calculate the df for between IV levels? (ANOVA)
no. of levels of IV-1
how do you calculate the df for within IV levels? (ANOVA)
sample size - no. of IV levels
what does partial eta^2 show?
What proportion of the variance in the DV is accounted for by the manipulation of the IV?
how do you calculate partial eta^2?
sum of square for the mean (what ur measuring)/
sum of square for the mean (what ur measuring) + sum of square for the mean (error of what ur measuring)
OR
sum of square for the mean (between)/
sum of square for the mean (between) + sum of square for the mean (wihtin)
how do you interpret a partial eta^2 value, eg 0.204
=20% of the variance in the DV was accounted for by the manipulation of the IV
If you had a study with 1 IV, >2 levels and was a between participants deign, what statistical test would you use?
1-way independent ANOVA
what is the non-parametric equivalent to the independent 1-eay ANOVA?
Kruskal Wallis Test
Which test checks the homogeneity of variance?
Levene’s
How do you write the test statistic for an independent 1-way ANOVA
F(dfM,dfR) = F-value, p = p-value
What is the correct post-hoc test for an independent 1-way ANOVA?
Tukey HSD
