Analysis of Variance

Analysis of Variance

The ANOVA table has 4 forms:
 Source   DF             F_inc
 Source   DF             F_inc  F_con M
 Source   DF  DDF_add    F_inc            P_add
 Source   DF  DDF_con    F_inc  F_con M   P_con
depending on whether conditional F-statistics are reported (requested by the !FCON qualifier ) and whether the denominator degrees of freedom are reported.

ASReml always reports incremental F-statistics ( F_inc) for the fixed model terms (in the DENSE partition) conditional in the order the terms were nominated in the model. Users should consult the Theory chapter of the User Guide for details of this table.

The 'conditional maximum' model used as the basis for the conditional F-statistic is spelt out in the .aov file.

The numerator degrees of freedom for each term is easily determined as the number of non-singular equations involved in the term. However, in general, calculation of the denominator degrees of freedom is not trivial. ASReml will by default attempt the calculation for small analyses, by one of two methods. In larger analyses, users can request the calculation be attempted using the !DDF qualifier. Use !DDF -1 to prevent the calculation.

See Also

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