Title: Standard Errors and Null-Hypothesis Significance Tests for Reliability Coefficients Author: L. Andries van der Ark Abstract: Reliability analysis is one of the most conducted analyses in applied psychometrics. It entails the assessment of reliability of both item scores and scale scores using coefficients that estimate the reliability (e.g. Cronbach’s alpha), estimate measurement precision (e.g., estimated standard error of measurement), or estimate the contribution of individual items to the reliability (e.g., corrected item-total correlations). Most statistical software packages used in the social and behavioral sciences offer these reliability coefficients. Standard errors and null-hypothesis significance tests (NHSTs) are generally unavailable for reliability coefficients, which is a bit ironic for coefficients that are about measurement precision. For a large number of coefficients, I derived standard errors and NHSTs. In this presentation, I will discuss the dilemmas and challenges of this task. In particular, I will discuss (1) categorical marginal models (CMMs), which I used as a framework for finding the correct sampling distributions of reliability statistics, (2) the challenges of estimating CMMs when a large number of items is involved, and (3) the challenges of developing user-friendly R software. Finally, I will show what I think reliability-analysis computer output should look like in the future.