This paper applies the techniques of Item Response Theory (IRT) to data from the Statistics Concept Inventory (SCI). Based on results from the Fall 2005 post-test (n = 422 students), the analyses of IRT are compared with those of Classical Test Theory (CTT). The concepts are extended to discussions of other applications, such as computerized adaptive testing and Likertscale items which may be o...

This paper reviews the problems associated with using IRT-based latent variable scores for analytical modeling, discusses the connection between IRT and SEM-based latent regression modelling for discrete data, and compares regression parameter estimates obtained using predicted IRT scores and standardized Number-Right scores in OLS regression with regression estimates obtained using the combine...

Punctual mutations in the TEM-1 or TEM-2 gene may lead to inhibitor-resistant-TEM (IRT) beta-lactamases with resistance to beta-lactam-beta-lactamase inhibitor combinations and susceptibility to cephalosporins. The aim of this work was to analyze the current epidemiology of IRT beta-lactamases in contemporary clinical Escherichia coli. Isolates were prospectively collected in our hospital (2007...

BACKGROUND Intensive residential treatment (IRT) is effective for severe, treatment-resistant obsessive-compulsive disorder (OCD). We sought to characterize predictors and course of response to IRT. METHODS Admission, monthly, and discharge data were collected on individuals receiving IRT. We examined the association between baseline characteristics and percent change in OCD symptoms as measu...

Item response theory (IRT) is concerned with accurate test scoring and development of test items. You design test items to measure various kinds of abilities (such as math ability), traits (such as extroversion), or behavioral characteristics (such as purchasing tendency). Responses to test items can be binary (such as correct or incorrect responses in ability tests) or ordinal (such as degree ...

BACKGROUND Previous cost-effectiveness studies using data from the literature showed that newborn screening for cystic fibrosis (NBSCF) is a good economic option with positive health effects and longer survival. METHODS We used primary data to compare cost-effectiveness of four screening strategies for NBSCF, i.e. immunoreactive trypsinogen-testing followed by pancreatitis-associated protein-...

OBJECTIVES To determine the effect of cloned inhibitor-resistant TEM beta-lactamases (IRTs) on the susceptibility of Haemophilus influenzae to amoxicillin/clavulanate. METHODS IRT-2, -4 and -5 genes with various promoters were cloned into control strains of H. influenzae and the amoxicillin/clavulanate MICs were measured using Etests. RESULTS IRT enzymes were able to raise the amoxicillin/c...

In the present research, we used item response theory (IRT) to examine whether effective predictions (anticipated affect) conforms to a typical (i.e., what people usually do) or a maximal behavior process (i.e., what people can do). The former, correspond to non-monotonic ideal point IRT models, whereas the latter correspond to monotonic dominance IRT models. A convenience, cross-sectional stud...

Item response theory (IRT) models are commonly used in the realm of educational and psychological testing. The three commonly used IRT models for responses that are graded as either correct or incorrect are the One-parameter, Two-parameter, and Three parameter IRT models. These models are used to calibrate standardized tests and to assess human latent traits such as student’s overall intelligen...