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POISSON REGRESSION 
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Call: glm(formula = y4 ~ logA + logB + trt, family = "poisson", 
                    data = seizure)
Deviance Residuals:
      Min       1Q    Median        3Q      Max 
 -3.61424 -1.12863 0.1963652 0.7722608 3.596213

Coefficients:
                 Value Std. Error    t value 
(Intercept) -3.3826380 0.90002865  -3.758367
       logA  0.3752060 0.23394327   1.603833
       logB  1.1990485 0.06920587  17.325821
        trt -0.1439681 0.10233126  -1.406883

(Dispersion Parameter for Poisson family taken to be 1 )

    Null Deviance: 476.2487 on 58 degrees of freedom

Residual Deviance: 144.3189 on 55 degrees of freedom

Number of Fisher Scoring Iterations: 4 

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POISSON REGRESSION with Scale Overdispersion
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Call: glm(formula = y4 ~ logA + logB + trt,
                     family = quasi(link = log, variance = mu),
                     data = seizure)
Deviance Residuals:
      Min       1Q    Median        3Q      Max 
 -3.61424 -1.12863 0.1963652 0.7722608 3.596213

Coefficients:
                 Value Std. Error     t value 
(Intercept) -3.3826380  1.4103320  -2.3984693
       logA  0.3752060  0.3665857   1.0235151
       logB  1.1990485  0.1084446  11.0567835
        trt -0.1439681  0.1603516  -0.8978273

(Dispersion Parameter for Quasi-likelihood family taken to be 2.455444 )

    Null Deviance: 476.2487 on 58 degrees of freedom

Residual Deviance: 144.3189 on 55 degrees of freedom

Number of Fisher Scoring Iterations: 4 

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NEGATIVE BINOMIAL REGRESSION 
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Call: glm.nb(formula = y4 ~ logA + logB + trt, data = seizure, 
                       init.theta = 5.71243750071843, link = log)
Deviance Residuals:
       Min         1Q      Median        3Q      Max 
 -2.689207 -0.9382149 -0.02600023 0.4486225 2.111726

Coefficients:
                 Value Std. Error    t value 
(Intercept) -2.6141220  1.3668926 -1.9124560
       logA  0.2822893  0.3659949  0.7712929
       logB  1.0912501  0.1127404  9.6793160
        trt -0.3062523  0.1612007 -1.8998207

(Dispersion Parameter for Negative Binomial family taken to be 1 )

    Null Deviance: 197.9498 on 58 degrees of freedom

Residual Deviance: 71.59166 on 55 degrees of freedom

Number of Fisher Scoring Iterations: 1 

              Theta:  5.71 
          Std. Err.:  2.15 

 2 x log-likelihood:  1216.246 

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Note:  1/5.71 = 0.1751
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