PURPOSE The present work describes how vocabulary ability as assessed by 3 different forms of the Peabody Picture Vocabulary Test (PPVT; Dunn & Dunn, 1997) can be placed on a common latent metric through item response theory (IRT) modeling, by which valid comparisons of ability between samples or over time can then be made. METHOD Responses from 2,625 cases in a longitudinal study of 697 pers...

Uniform diagnostic criteria for the night eating syndrome (NES), a disorder characterized by a delay in the circadian pattern of eating, have not been established. Proposed criteria for NES were evaluated using item response theory (IRT) analysis. Six studies yielded 1,481 Night Eating Questionnaires which were coded to reflect the presence/absence of five night eating symptoms. Symptoms were e...

1560 CLINICAL CHEMISTRY, Vol. 29, No. 8, 1983 universal phenylketonuria/hypothyroidism screen. The project was based on an hypothesis first outlined by Crossley et al. (1), viz., that an abnormally high blood IRT value for a newborn is suggestive of cystic fibrosis (CF). Details of the methods were previously described (2). We tested 25 000 newborns and identified seven infants confirmed to hav...

Infrared thermography (IRT) is a real-time non-contact diagnostic tool with a broad potential for neurosurgical applications. Here we describe the intraoperative use of this technique in a single patient with newly diagnosed glioblastoma multiforme (GBM). An 86-year-old female was admitted in the clinic with a 2-month history of slowly progressing left-sided paresis. Neuroimaging studies demons...

Most studies of the Flynn Effect (FE) use classical test theory (CTT)-derived scores, such as summed raw scores. In doing so, they cannot test competing hypotheses about FE, such as it is caused by a real change in cognitive ability versus it is a change in the tests that measure cognitive ability. An alternative to CTTderived scores is to use latent variable scores, such as those from item res...

Since BC 400 when Hippocrates used temperature in a diagnosis by applying mud to a patient's body and speculating that dry areas had disease, temperature has been an important area of interest in medicine. The skin is a very important organ in temperature regulation, and body temperature is controlled by the combined control of the central and autonomic nerve system. Infrared thermography (IRT)...

Computer adaptive testing is the study of scoring tests and questions based on assumptions concerning the mathematical relationship between examinees’ ability and the examinees’ responses. Adaptive student tests, which are based on item response theory (IRT), have many advantages over conventional tests. We use the least square method, a well-known statistical method, to reach an estimation of ...

A remarkable feature of the prototype foamy virus (PFV) replication pathway has been reported to consist of the ability to retrotranspose intracellularly with high efficiency (M. Heinkelein, T. Pietschmann, G. Jármy, M. Dressler, H. Imrich, J. Thurow, D. Lindemann, M. Bock, A. Moebes, J. Roy, O. Herchenröder, and A. Rethwilm, EMBO J. 19:3436-3345, 2000). PFV intracellular retrotransposition (IR...

A subset S of vertices in a graph G is called a total irredundant set if, for each vertex v in G, v or one of its neighbors has no neighbor in S − {v}. The total irredundance number, ir(G), is the minimum cardinality of a maximal total irredundant set of G, while the upper total irredundance number, IR(G), is the maximum cardinality of a such set. In this paper we characterize all cubic graphs ...

This study aimed at examining the issues affecting the use of IRT models in investigating differential item functioning in high stakes testing. It specifically focused on the Iranian National University Entrance Exam (INUEE) Special English Subtest. A sample of 200,000 participants was randomly selected from the candidates taking part in the INUEE 2003 and 2004 respectively. The data collected ...