Dear mixed model experts,



I used the generalized linear models (GLM) to explore the dietary effects
entering the number of offspring sired by both groups as the response
variable (y), dietary treatment as a fixed effect (treat which has two
levels - High and Low), family as a random effect with a binomial error
distribution and a logit link function. The model was weighted by total
number of offspring, and observation-level was included in the full model
as a random effect to approximate overdispersion which reduced the
dispersion parameter from 3.39 to 1.02. The output is below:



y=cbind(Data$Success,Data$Failure)


Generalized linear mixed model fit by the Laplace approximation

Formula: y ~ treat + (1 | Family) + (1 | obs)

   Data: Data

   AIC   BIC logLik deviance

 198.6 206.4 -95.28    190.6

Random effects:

 Groups Name        Variance Std.Dev.

 obs    (Intercept) 1.0383   1.019

 Family (Intercept) 0.0000   0.000

Number of obs: 52, groups: obs, 52; Family, 26



Fixed effects:

            Estimate Std. Error z value Pr(>|z|)

(Intercept)   0.5664     0.2124   2.667 0.007658 **

treatLH      -1.1329     0.3004  -3.772 0.000162 ***

---

Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1



Correlation of Fixed Effects:

        (Intr)

treatLH -0.707



The result gives only the effect of Low dietary group (treatLH). I know
also how to see the effect of High group excluding intercept with the
following formula:

Fixed effects:

        Estimate Std. Error z value Pr(>|z|)

treatHH   0.5664     0.2124   2.667  0.00766 **

treatLH  -0.5665     0.2124  -2.667  0.00765 **



I also know some experts suggest for likelihood-ratio test. But first of
all, I'd like to see the effects of treat on y (not individual effect of
High or Low group) like ANOVA.



Can anyone suggest how to get it? If it's not possible, how can I report
the existing results for my thesis?



Any advice will be highly appreciated.



Cheers,



Moshi

-- 
MD. MOSHIUR RAHMAN
PhD Candidate
School of Animal Biology/Zoology (M092)
University of Western Australia
35 Stirling Hwy, Crawley, WA, 6009
Australia.
Mob.: 061-425205507

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