Checking for overdispersion
In this exercise you will check for overdispersion in the model you fitted previously, namely the horseshoe crab Poisson model where you fitted sat given width. Recall from the video that to check for potential overdispersion in the fit you would compute the following
model.pearson_chi2 / model.df_resid
where .pearson_chi2 represents Pearson statistic and .df_resid represents the degrees of freedom of the residuals.
The model crab_pois and crab dataset are preloaded in the workspace.
Este exercício faz parte do curso
Generalized Linear Models in Python
Instruções do exercício
- Compute the ratio of the Pearson statistic and the degrees of freedom of the residuals for the
crab_poisPoisson regression model.
Exercício interativo prático
Experimente este exercício completando este código de exemplo.
# Compute and print the overdispersion approximation
____(____.____ / ____.____)