Darryl Laws
Log likelihood. Had I conducted the research I would have chosen to use log likelihood statistic to assess and to depict the deviance, or -2 log-likelihood (-2LL) statistic . The deviance is basically a measure of how much unexplained variation there is in our logistic regression model the higher the value the less accurate the model. It compares the difference in probability between the predicted outcome and the actual outcome for each case and sums these differences together to provide a measure of the total error in the model. This is similar in purpose to looking at the total of the residuals (the sum of squares ) in linear regression analysis in that it provides us with an indication of how good our model is at predicting the outcome. The -2LL statistic (often called the deviance) is an indicator of how much unexplained information there is after the model has been fitted, with large values of -2LL indicating poorly fitting models. The de...