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What is an uninformative prior?
An uninformative prior or diffuse prior expresses vague or general information about a variable. The term “uninformative prior” is somewhat of a misnomer. Such a prior might also be called a not very informative prior, or an objective prior, i.e. one that’s not subjectively elicited.
Where can I find Jeffreys prior?
We can obtain Jeffrey’s prior distribution pJ(ϕ) in two ways:
- Start with the Binomial model (1) p(y|θ)=(ny)θy(1−θ)n−y.
- Obtain Jeffrey’s prior distribution pJ(θ) from original Binomial model 1 and apply the change of variables formula to obtain the induced prior density on ϕ pJ(ϕ)=pJ(h(ϕ))|dhdϕ|.
What is Bayesian logistic regression model?
Bayesian logistic regression has the benefit that it gives us a posterior distribution rather than a single point estimate like in the classical, also called frequentist approach. When combined with prior beliefs, we were able to quantify uncertainty around point estimates of contraceptives usage per district.
How to calculate Jeffreys prior for a normal distribution?
According to my calculations, the following holds for Jeffreys prior: p(μ, σ2) = √det(I) = √det(1 / σ2 0 0 1 / (2σ4)) = √ 1 2σ6 ∝ 1 σ3. Here, I is Fisher’s information matrix. p(μ, σ2) ∝ 1 / σ2 see Section 2.2 in Kass and Wassermann (1996). as Jeffreys prior for the case of a normal distribution with unkown mean and variance.
Is the Jeffreys prior a physically correct prior?
To have a physically correct prior, you need it to have the right dimensions, i.e. the only powers of σ physically possible in a non-parametric prior are: π(μ, σ) ∼ 1 / σ2 and π(μ, σ2) ∼ 1 / σ3 . 1 σ3 is the Jeffreys prior.
What are the arguments for Stan _ POLR and Stan _ gamm4?
The stan_polr, stan_betareg, and stan_gamm4 functions also provide additional arguments specific only to those models: Prior for hyperparameters in GAMs (lower values yield less flexible smooth functions). Prior counts of an ordinal outcome (when predictors at sample means).
Which is the prior for Stan GLM in rstanarm?
* stan_glm also implies stan_glm.nb. stan_glmer implies stan_lmer and stan_glmer.nb. The stan_polr, stan_betareg, and stan_gamm4 functions also provide additional arguments specific only to those models: Prior for hyperparameters in GAMs (lower values yield less flexible smooth functions).