Markov chain Monte Carlo Estimation Practice in Psychometric Models Stochastic estimation processes known as Markov chain Monte Carlo (MCMC) methods have drawn an increasing amount of attention in statistics within the last twenty years. MCMC provides a virtually universal tool to deal with integration (and optimization) problems, and this estimation method gives us the possibility of solving some of the challenges associated with the traditional gradient-based maximum likelihood (ML) method. The main purpose of this presentation is to introduce MCMC estimation and illustrate its practice to a variety of psychometric models, including structural equation modeling (SEM) and item response theoretic (IRT) models.