Nonparametric Three or more groups

Kruskal-Wallis Analysis of Variance of Ranks Test 1.Kruskal-Wallis Analysis of Variance of Ranks Test

Example 1.A police psychologist wants to determine whether relaxation or guided imagery enhance the rank- orderings of the crime-solving abilities of police officers. He/she compares them to a control group. 2.6 in the control group, 6 in relaxation, 6 in imagery

Example -- continued 1.Number of Samples: 2.Nature of Samples: 3.σ Known: 4.Independent Variable:

Example -- continued 5.Dependent Variable and its Level of Measurement: 6.Target Population: 7.Inferential Statistical Technique: 1. Kruskal-Wallis Analysis of Variance of Ranks Test

Example -- continued 8.H 0 : 1. Type of training will have no effect on rank- ordered crime-solving ability 9.H 1 : 1. Type of training will have an effect on rank- ordered crime-solving ability 10.Decision Rule: 1. If the p-value of the obtained test statistic is less than.05, reject the null hypothesis

Example -- continued 11.Obtained Test Statistic: 1.χ 2 (2) = 5.96, p = Decision:

Results Section 1.The results of the Kruskal-Wallis Analysis of Variance of Ranks Test involving type of training as the independent variable and rank- ordered crime-solving ability as the dependent variable were not statistically significant, χ 2 (2) = 5.96.

Discussion Section 1.It appears that the type of training police officers receive has no effect on rank-ordered crime-solving ability

Kruskal-Wallis Test and SPSS for Windows Statistics, Nonparametric Tests, k Independent Samples Move DV to Test Variable list Move IV to Grouping Variable Define Groups Make sure K-W is checked

Interpreting the Printout Mean ranks Chi-Square (obtained test statistic) Significance (p-value)

Sample Printout