Psychology Commons^™

A Positive Trait Item Response Model, Joseph F. Lucke

Joseph Lucke

All current models from item response theory (IRT) assume the latent trait follows a standard normal distribution. While this assumption is appropriate for traits such as ability or attitude, it creates both conceptual and technical problems traits such as addiction (alcohol, drugs, gambling). The distribution of an addiction trait is better assumed to be anchored at zero (no addiction) and positively skewed. A small change to the usual IRT model yields a class of positive-trait item response models (PTIRMs). I discuss PTIRMs and present one model in detail, including item characteristic curves and item information curves. I present an example …

Positive Trait Item Response Models, Joseph F. Lucke

Joseph Lucke

A new item response model is proposed for which the trait is positive. Three such models, the loglogistic, the log-normal, and the Weibull, are presented along with their item information curves. The data of seven addiction items from the DSM-IV from a study on alcohol addiction is analyzed by these three models using Bayesian Markov chain Monte Carlo methods. The item characteristic curves and item information curves are presented for all three models. The person scores for four item response patterns are presented for the log-logistic model.

Predicting Breast-Feeding Attrition: Adapting The Breast-Feeding Attrition Prediction Tool, Elizabeth Reifsnider, Sarah L. Gill, Joseph F. Lucke, Angela R. Mann

Joseph Lucke

CONTEXT: Current breast-feeding rates fall short of the recommendations set forth in Health People 2010. The Breast-feeding Attrition Prediction Tool (BAPT), administered in the postpartum period, has been useful in predicting breast-feeding attrition. However, assessing a woman's intention to breast-feed prior to birth would identify women at risk for breast-feeding attrition.

PURPOSE: The purpose of this study was to describe a revised BAPT, administered antepartally that measures intention to breast-feed.

METHODS: The BAPT, comprising 94 items on a 6-point Likert-type scale, was translated into Spanish and back-translated for accuracy. The BAPT was then revised by reducing the number of items …

"Rassling The Hog": The Influence Of Correlated Item Error On Internal Consistency, Classical Reliability, And Congeneric Reliability, Joseph F. Lucke

Joseph Lucke

The properties of internal consistency ($\alpha$), classical reliability ($\rho$), and congeneric reliability ($\omega$) for a composite test with correlated item error were analytically investigated. Possible sources of correlated item error are contextual effects, item bundles, and item models that ignore additional attributes or higher-order attributes. The relation between reliability and internal consistency is determined by the deviance from true-score equivalence. Reliability (classical or congeneric) is internal consistency plus the relative deviance from true-score equivalence. The influence of correlated item error on $\alpha$, $\rho$, and $\omega$ is conveyed strictly through the total item error covariance. As the total item error covariance …

The $\Alpha$ And The $\Omega$ Of Congeneric Test Theory: An Extension Of Reliability And Internal Consistency To Heterogeneous Tests, Joseph F. Lucke

Joseph Lucke

Psychometric theory focuses primarily on tests that are homogeneous, that measure only one attribute of a psychosocial entity. However, the complexity of psychosocial behavior often requires tests that are heterogeneous, that measure more than one attribute. In this presentation, reliability and internal consistency are extended to heterogeneous tests under the rubric of congeneric test theory. The extensions show that reliability and internal consistency have very similar properties. Reliability and internal consistency are shown to be unique up to a linear transformation. Whereas internal consistency is a lower bound to reliability in the homogeneous case, it is a strict lower bound …