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Interpreting the Results of GLM

2 messages · sazzle, Milan Bouchet-Valat

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Hi, I'm wondering if you can help me, this is a really simple query but I
keep getting confused.  I have run a GLM to see how boldness varies over
time following a particular treatment.  The results are as follows... 

Call: glm(formula = boldtwentyfour ~ treatment + boldcontrol)
Deviance Residuals: 
    Min       1Q   Median       3Q      Max  
-1.7577  -0.5469   0.0456   0.5515   1.5327  
Coefficients:  Estimate Std. Error t value Pr(>|t|)  
(Intercept)    0.8312     0.5444   1.527   0.1363  
treatmentPBS   0.1391     0.2842   0.490   0.6277  
boldcontrol    0.4899     0.2157   2.271   0.0298 *
Signif. codes:  0 ?***? 0.001 ?**? 0.01 ?*? 0.05 ?.? 0.1 ? ? 1 
(Dispersion parameter for gaussian family taken to be 0.7131691)
Null deviance: 27.243  on 35  degrees of freedom
Residual deviance: 23.535  on 33  degrees of freedom
AIC: 94.862  Number of Fisher Scoring iterations: 2

Basically, where I am having trouble is that I have several GLMs like this
and need to display the results in a table and am required to display the
intercept, estimates, 95% confidence and the errors.  I am confused as to
which values are which as for the intercept there are four different values
which all seem to relate to everything else I need to report, while
everything else would go unreported.  From this table of output from R can
you help me to identify which value is which? 
Thanks, 
Sarah.


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Le mardi 28 f?vrier 2012 ? 02:48 -0800, sazzle a ?crit :
I don't understand this sentence, sorry. ;-)
The values of the coefficients as estimated by the model are in the
first column, "Estimate". The value of the intercept is reported the
same way as the coefficients, so it's in the "Estimate" column of the
"(Intercept)" row.

Standard errors are reported, well, in the "Std. Error" column, for each
coefficient (including the intercept). If you need the 95% confidence
interval, see ?confint.


Hope this helps