I am running a logistic regression, with Gender as the predictor. My issue is that when including "School", which has levels A-X, into the model I obtain this in the summary output:
> glm.1=glm(Gender~Math.Scaled.Scores.2011+Math.Scaled.Scores.2012+Math.Scaled.Scores.2013+School, data= Ed, family=binomial)
> summary(glm.1)
Call:
glm(formula = Gender ~ Math.Scaled.Scores.2011 + Math.Scaled.Scores.2012 + 
    Math.Scaled.Scores.2013 + School, family = binomial, data = Ed)
Deviance Residuals: 
   Min      1Q  Median      3Q     Max  
-1.389  -1.212   1.058   1.138   1.376  
Coefficients:
                          Estimate Std. Error z value Pr(>|z|)  
(Intercept)              3.331e-02  2.223e-01   0.150   0.8809  
Math.Scaled.Scores.2011 -7.837e-04  5.401e-04  -1.451   0.1468  
Math.Scaled.Scores.2012  5.279e-05  6.298e-04   0.084   0.9332  
Math.Scaled.Scores.2013  9.878e-04  6.258e-04   1.579   0.1144  
SchoolB                  5.198e-03  2.091e-01   0.025   0.9802  
SchoolC                 -3.341e-02  2.120e-01  -0.158   0.8748  
SchoolD                 -6.354e-02  2.348e-01  -0.271   0.7867  
SchoolE                  9.032e-03  2.159e-01   0.042   0.9666  
SchoolF                 -3.553e-01  2.322e-01  -1.530   0.1260  
SchoolG                 -1.845e-01  2.325e-01  -0.794   0.4274  
SchoolH                 -2.358e-01  2.308e-01  -1.022   0.3069  
SchoolI                  1.351e-02  2.162e-01   0.062   0.9502  
SchoolJ                  1.220e-01  2.395e-01   0.509   0.6105  
SchoolK                 -3.845e-02  2.388e-01  -0.161   0.8721  
SchoolL                 -1.637e-02  2.018e-01  -0.081   0.9354  
SchoolML                 1.051e-01  2.304e-01   0.456   0.6483  
SchoolN                  4.214e-02  2.310e-01   0.182   0.8552  
SchoolO                 -1.764e-02  2.248e-01  -0.078   0.9374  
SchoolP                  3.455e-02  2.258e-01   0.153   0.8784  
SchoolQ                 -2.496e-01  2.066e-01  -1.208   0.2270  
SchoolR                 -4.046e-01  2.187e-01  -1.851   0.0642 .
SchoolS                  1.483e-02  2.139e-01   0.069   0.9447  
SchoolT                 -2.566e-01  2.334e-01  -1.100   0.2714  
SchoolU                 -4.166e-02  2.088e-01  -0.199   0.8419  
SchoolV                 -4.073e-01  2.246e-01  -1.813   0.0698 .
SchoolW                  1.074e-03  2.203e-01   0.005   0.9961  
SchoolX                 -1.056e-01  2.190e-01  -0.482   0.6298  
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
(Dispersion parameter for binomial family taken to be 1)
    Null deviance: 5997.2  on 4327  degrees of freedom
Residual deviance: 5971.4  on 4301  degrees of freedom
AIC: 6025.4
Number of Fisher Scoring iterations: 3
It gives all the coeffiecients for each school, but I want it to be "School" in general as a whole, not schoolA-Schoolz. So it looks like I have 24 predictors of school, when I really only want 1.
