Exploration & description/ANOVA or REML?

The output on the right shows the results for the least squares analysis of variance and parameter estimates but without interaction.

We shall next run the model through the REML procedure (Stats → Mixed Models (REML)→ Linear Mixed Models) and compare with that obtained by least squares analysis of variance.

A description of how the REML analysis can be conducted in R is illustrated in Mbunzi and Nagda (2009).

 
*** Regression ***
Response variate: WEANWT
Fitted terms: Constant + YEAR + SEX + AGEWEAN + DL + DQ + RAM_BRD + EWE_BRD

***Estimates of parameters***

 Estimate

s.e.

t(688)

tpr.

Constant

12.95

1.07

0.26

0.797

YEAR 92

-1.566

0.293

-5.35

<.001

YEAR 93

-1.096

0.275

-3.98

<.001

YEAR 94

-2.833

0.358

-7.92

<.001

YEAR 95

-3.228

0.344

-9.39

<.001

YEAR 96

-2.351

0.390

-6.03

<.001

SEX M

0.478

0.169

2.82

0.005

AGEWEAN

0.07022

0.00886

7.93

<.001

DL

2.726

0.315

8.65

<.001

DQ

-0.2689

0.0340

-7.91

<.001

RAM_BRD R

-0.443

0.173

-2.56

0.011

EWE_BRD R

-0.586

0.237

-2.48

0.014

***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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