# IRT

## Estimating a 2-PL Model in Julia (Part 2)

E-Step M-Step Estimating a 2-PL Model with EM in Julia Find $$\bar r_{jk}$$ and $$\bar n_k$$ Solve estimating equations Iterations Stopping criteria Benchmarking Remark $\newcommand{\bv}[1]{\boldsymbol{\mathbf{#1}}}$

## Estimating a 2-PL Model in Julia (Part 1)

Import Data Two-Parameter Logistic Model Estimation with mirt in R Marginal Maximum Likelihood (MML) Estimation Implement MML Estimation in Julia Import R data Compute marginal loglikelihood Optimization Benchmarking The semester is finally over, and for some reason, I wanted to consolidate my understanding of some psychometric models, perhaps because I’ll be teaching a graduate measurement class soon.

## IRT Scoring With Covariates

I was working on an extension to the two-stage path analysis Lai & Hsiao (2021) related to integrative data analysis, and ran into an issue described in Davoudzadeh et al.

## Two-stage path analysis with definition variables: An alternative framework to account for measurement error

The proposed 2S-PA method, which estimated factor scores and the corresponding standard errors in the first stage, and use SEM with definition variables in the second stage, showed favorable performance in small samples compared to full SEM.