Chapter 17: Nonparamatric Tests- Kriskul-Wallis Test

Question 1

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)

Answer 1

• one way anova
• anova
• ordinal
• interval, ratio

Question 2

What are the assumptions for the kruskal wallis test?

Answer 2

1. at least ordinal

2. at least 5 in each group

Question 3

Null hypothesis for this test?

Answer 3

u1=u2=u3 etc

Question 4

Ha??

Answer 4

• at least one mean of the groups is different from at least one of the other groups mean.

Question 5

What statistic is being calculated for this test?

Answer 5

Hobt….
Hobt = [ 12/N(N+1)][E(Ri)^2/ni]-3(N+1)
** the summation part occurs for each group in the experiment!

Question 6

How are the scores ranked in this test?

Answer 6

• 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!

Question 7

In nonparametric tests such as this one…what is analysis looking at in terms of scores etc?

Answer 7

• its looking at the ranks not the actual scores!

L> a reason why they are less powerful than parametric tests….

Question 8

How does this test get done in SPSS?

Answer 8

1. enter data just you would with an ANOVA. (raw data is all put into one column and group variables are assigned to identify the group)
2. Analysis—> nonparametric–>legacy dialogues—> K-independent sample
3. DV goes into test list
   L> group goes to grouping variable ox
   L> defined: min=1, x=max-3 (groups)