Exploration & description/ANOVA or REML?

The table for the Wald tests shows that the main effects of ram breed and ewe breed, when adjusted for ram breed, are significant with Wald statistics of 9.10 and 6.13. when compared with Chi-square values with 1 degree of freedom, P=0.003 and 0.013, respectively.

Although not shown, virtually the same P-values are obtained when applying F-tests to the mean squares in the least squares analysis of variance.

 
***** REML Variance Components Analysis *****
Response Variate : WEANWT

*** Approximate stratum variances ***
                                      Effective d.f.
*units*            4.933         688.00
*** Wald tests for fixed effects ***

Fixed term

Wald statistic

d.f.

Wald/d.f.

Chi-sq prob

* Sequentially adding terms to fixed model

YEAR

244.93

   5

48.99

<0.001

SEX

11.35

   1

11.35

<0.001

AGEWEAN

69.78

   1

69.78

<0.001

DL

30.72

   1

30.72

<0.001

DQ

55.91

   1

55.91

<0.001

RAM_BRD

9.10

   1

9.10

0.003

EWE_BRD

6.13

   1

6.13

0.013

Least Squares analysis
Accumulated analysis of variance

Change

d.f

s.s.

m.s.

v.r.

+ YEAR

5

1208.149

241.630

48.99

+ SEX

1

55.983

55.983

11.35

+ AGEWEAN

1

344.206

344.206

69.78

+ DL

1

151.513

151.513

30.72

+ DQ

1

275.795

275.795

55.19

+ RAM_BRD

1

44.881

44.881

9.10

+ EWE_BRD

1

30.223

30.223

6.13

Residual

688

3393.701

4.933

 


Total


699


5504.450


7.875

 

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