[R] lme() F-values disagree with aov()

William Simpson wsimpson at utsc.utoronto.ca
Mon Aug 14 16:56:16 CEST 2006


> Your lme statement is OK. To get the usual split-plot anova, your aov
> statement should be
>
> fit2 <- aov(y ~ a*b*c + Error(s), data = d)

No, this gives wrong F-values. By "wrong" I mean it does not agree with the
published table.

Table 12.10-2, page 559:
                     Number of obs =      32     R-squared     =  0.9920
                     Root MSE      = .559017     Adj R-squared =  0.9589

            Source |  Partial SS    df       MS           F     Prob > F
        -----------+----------------------------------------------------
             Model |     233.625    25       9.345      29.90     0.0002
                   |
                 a |       3.125     1       3.125       2.00     0.2070
               s|a |       9.375     6      1.5625
        -----------+----------------------------------------------------
                 b |      162.00     1      162.00     199.38     0.0000
               a*b |       6.125     1       6.125       7.54     0.0335
             b*s|a |       4.875     6       .8125
        -----------+----------------------------------------------------
                 c |       24.50     1       24.50      61.89     0.0002
               a*c |      10.125     1      10.125      25.58     0.0023
             c*s|a |       2.375     6  .395833333
        -----------+----------------------------------------------------
               b*c |        8.00     1        8.00      25.60     0.0023
             a*b*c |       3.125     1       3.125      10.00     0.0195
                   |
          Residual |       1.875     6       .3125
        -----------+----------------------------------------------------
             Total |      235.50    31  7.59677419

Bill



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