Flashcards in Chapter 17: Nonparamatric Tests- Kriskul-Wallis Test Deck (8):
The kruskal wallis test is used in place of the _____ when there is an extreme violation of at least one assumption of the ____. Requires at least __ scaling of DV. (or ___ and ___ is required but not met)
-one way anova
What are the assumptions for the kruskal wallis test?
1. at least ordinal
2. at least 5 in each group
Null hypothesis for this test?
- at least one mean of the groups is different from at least one of the other groups mean.
What statistic is being calculated for this test?
Hobt = [ 12/N(N+1)][E(Ri)^2/ni]-3(N+1)
** the summation part occurs for each group in the experiment!
How are the scores ranked in this test?
- you rank across all conditions together as if all in one condition!
- no negative ranks
L> Ri= sum of ranks in that condition
L> do not use absolute values.... sign means something!
In nonparametric tests such as this one...what is analysis looking at in terms of scores etc?
- its looking at the ranks not the actual scores!
L> a reason why they are less powerful than parametric tests....