Logistic regression uses the log-likelihood statistic to evaluate the fit of a model, based on the predicted and observed values, and is closely related to the deviance, but how is deviance expressed?
A) Deviance = -2 × log-likelihood
B) Deviance = -2 / log-likelihood
C) Deviance = log-likelihood / (-2)
D) Deviance = log-likelihood / ((-2) × (-2))

Question

Quizplus · Accepted Answer

Deviance is expressed as -2 times the natural logarithm of the ratio of the likelihood of the null model to the likelihood of the fitted model. Therefore, the correct expression for deviance is Deviance = -2 × log-likelihood.

Logistic Regression Uses the Log-Likelihood Statistic to Evaluate the Fit