Page 185 - Applied Statistics Using SPSS, STATISTICA, MATLAB and R
P. 185

4.5 Inference on More than Two Populations   165


                                    2-Way (2 X 3) ANOVA
                           Row Effect Power vs. N (RMSSE = 0.783055, Alpha = 0.05)
                     1.00



                     .95

                   Power  .90






                     .85


                                                          Group Sample Size (N)
                     .80
                       0       5       10      15     20      25      30
                    Figure 4.22. Power curve for the row effect of Example 4.22.

              The power values computed by STATISTICA are 0.90, 1.00 and 0.97 for the
           rows, columns and interaction, respectively.
              The power curve for the row effects, dependent on n is shown in Figure 4.22.
           We see that we need at least 8 cases per cell in order to achieve a row effect power
           above 95%.

           Commands 4.6.  SPSS,  STATISTICA,  MATLAB and R commands  used to
           perform the two-way ANOVA test.

             SPSS          Analyze; General Linear Model;
                           Univariate|Multivariate

                           Statistics; ANOVA; Factorial ANOVA
             STATISTICA    Statistics; Advanced Linear/Nonlinear
                           Models; General Linear Models; Main
                           effects ANOVA | Factorial ANOVA

             MATLAB        [p,table]=anova2(x,reps,’dispopt’)

             R             anova(lm(X~f1f*f2f))



           The easiest commands to  perform the  two-way  ANOVA test  with SPSS and
           STATISTICA are  General Linear Model; Univariate         and ANOVA  ,
           respectively.  Contrasts in STATISTICA can be specified using the  Planned
           comps   tab.
   180   181   182   183   184   185   186   187   188   189   190