10/18/2010

Discussion of Exam #1

One Way ANOVA

• Setting
• Model
• Hypotheses
  • General Alternatives (Section 6.1)
  • Ordered Alternatives (Section 6.2)
  • Umbrella Alternatives (Section 6.3)
• Kruskal-Wallis Procedure
  • If k=2 then the Kruskal-Wallis test is equivalent to the Mann-Whitney-Wilcoxon test.
  • Combine all N observations and rank them from least to greatest.
  • Find the sum of the ranks for each treatment.
  • Find the average of the ranks for each treatment.
  • What should the average rank for each treatment be close to if the null hypothesis is true?
  • Kruskal-Wallis Statistic (H)
  • Kruskal-Wallis Test
    • Enter Table A.12 with increasing sample sizes to find the critical value.
  • L.S.A.
  • Dealing with ties (see H' on page 192)
    • Use a permutation test to get an exact p-value.
• Exercise 12 on p. 201
  • p:\data\math\nonparametrics\pine.mtw