Exponential Family

The exponential family of probability distributions is a unifying framework that encapsulates a broad class of continuous and discrete distributions. Entries under this tag explore natural parameters, sufficient statistics, conjugate priors, information geometry, and applications in Bayesian inference and machine learning.

📄 142 Articles 🔄 Last updated: November 2025 👁 28.4K monthly views

Exponential Family Distributions: A Complete Overview

A comprehensive introduction to the mathematical definition, canonical form, and key properties of the exponential family. Covers natural parameter space, base measures, and conditions for regularity.

Bernoulli Distribution as an Exponential Family Member

Derives the canonical representation of the Bernoulli distribution, identifies its natural parameter (log-odds), and demonstrates conjugate updating with the Beta prior in Bayesian inference.

Gaussian Distribution and Natural Parameters

Explores how the normal distribution fits into the exponential family framework, detailing the natural parameter vector (μ/σ², -1/2σ²), sufficient statistics, and connections to precision matrices.

Conjugate Priors in the Exponential Family

Explains why exponential family distributions naturally yield conjugate priors, derives the general form, and walks through practical examples including Dirichlet-Multinomial and Normal-Gamma models.

Poisson Distribution: Properties and Applications

Examines the Poisson distribution's exponential family representation, moment generating functions, and its role in modeling count data. Includes links to overdispersion alternatives like Negative Binomial.

Generalized Linear Models and Link Functions

Connects exponential family distributions to GLMs, explaining canonical link functions, iterative reweighted least squares (IRLS), and assumptions for regression with non-Gaussian responses.

Sufficient Statistics and Fisher Information

Details the relationship between exponential family structure, minimal sufficiency, and the Cramér-Rao lower bound. Includes derivations of Fisher information matrices and asymptotic normality.

Dirichlet Distribution and Multinomial Inference

Covers the Dirichlet as a conjugate prior for categorical and multinomial likelihoods, explores concentration parameters, posterior predictive distributions, and applications in topic modeling.