When we are performing maximum likelihood estimation (MLE) to estimate parameters, the fit function is often to -2 * LL, rather than just LL. I also see this "-2LL" term expressed as "deviance". Why do we multiply log likelihood times -2? Is it if we are trying to minimize the function rather than maximize? What is the purpose of it being multiplied by (a) a negative number, and (b) a "2"?
Some locations where "-2 log likelihood" is expressed are below: