BACKGROUND Many questionnaires for measuring physical activity (PA) exist. This complicates the comparison of outcomes. METHODS In 8 European countries, PA was measured in random samples of 600 persons, using the IPAQ as a 'bridge' to historical sets of country-specific questions. We assume that a unidimensional scale of PA ability exists on which items and respondents can be placed, irrespec...

BACKGROUND Modern psychometric methods based on item response theory (IRT) can be used to develop adaptive measures of health-related quality of life (HRQL). Adaptive assessment requires an item bank for each domain of HRQL. The purpose of this study was to develop item banks for five domains of HRQL relevant to arthritis. METHODS About 1,400 items were drawn from published questionnaires or ...

Item response theory (IRT) models typically rely on a normality assumption for subject-specific latent traits, which is often unrealistic in practice. Semiparametric extensions based Dirichlet process mixtures (DPMs) offer more flexible representation of the unknown distribution trait. However, use such IRT literature has been extremely limited, good part because lack comprehensive studies and ...

Background: Nonparametric item response theory (IRT) was used to examine (a) the performance of the 30 Positive and Negative Syndrome Scale (PANSS) items and their options ((levels of severity), (b) the effectiveness of various subscales to discriminate among differences in symptom severity, and (c) the development of an abbreviated PANSS (Mini-PANSS) based on IRT and a method to link scores to...

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...

OBJECTIVE To perform the first comprehensive psychometric evaluation of the Hypoglycemia Fear Survey-II (HFS-II), a measure of the behavioral and affective dimensions of fear of hypoglycemia, using modern test-theory methods, including item-response theory (IRT). RESEARCH DESIGN AND METHODS Surveys completed in four previous studies by 777 adults with type 1 diabetes were aggregated for analy...

BACKGROUND Nonparametric item response theory (IRT) was used to examine (a) the performance of the 30 Positive and Negative Syndrome Scale (PANSS) items and their options ((levels of severity), (b) the effectiveness of various subscales to discriminate among differences in symptom severity, and (c) the development of an abbreviated PANSS (Mini-PANSS) based on IRT and a method to link scores to ...

Though a substantial amount of research exists on imputing missing scores in educational assessments, there is little cases where responses or to an item are for all test takers. In this paper, we tackled the problem tests which We considered three missing-data imputation methods—the median method, response theory (IRT) and two-way method—for scores. compared performance these methods with resp...

Many previous studies related to self-regulated learning have demonstrated that students with higher academic achievement tend use varied and effective strategies. However, they cannot acquire these strategies in a short period. If are acquired used gradually, it may help specify individual levels of teach its usage reasonable order. Therefore, this study analyzed data on strategy item response...