What is Profile deviance?
deviance specifies the profile-deviance function, i.e., −2 times the PLL function. If difference is also specified, deviance produces the profile-deviance difference, i.e., −2 times the PLL difference. Pathological cases denote likelihood functions with multiple maximums or no maximum.
Can deviance profile be negative?
1 Answer. The global deviance reported by R is negative, the reason for this being the fact that the variability of the y observations about the fitted regression line is small. So it is possible to have a negative global deviance in this simple case if the model produces a low value for the residual sum of squares.
Is the confidence interval based on standard error?
In general, the confidence interval based on the standard error strongly depends on the assumption of normality for the estimator. The “profile likelihood confidence interval” provides an alternative.
When to use profile likelihood in interval estimation?
Profile likelihood is often used when accurate interval estimates are difficult to obtain using standard methods—for example, when the log-likelihood function is highly nonnormal in shape or when there is a large number of nuisance parameters .
When to use profile likelihood and log likelihood?
PROFILE LIKELIHOOD. Profile likelihood is often used when accurate interval estimates are difficult to obtain using standard methods—for example, when the log-likelihood function is highly nonnormal in shape or when there is a large number of nuisance parameters ( 7 ). Usually there will be 2 values for β 1, and ,…
What are the parameters in frequentist likelihood theory?
In frequentist likelihood theory, the parameters are fixed constants that govern the distribution of the observations, and probabilities are viewed as hypothetical long-run frequencies (hence the term “frequentist”).