Search results for " Rasch Model"
showing 10 items of 11 documents
Diagnostic delay in oral squamous cell carcinoma: the role of cognitive and psychological variables
2014
This retrospective study investigated, in two cohorts of subjects living in Southern Italy and awaiting treatment for oral squamous cell carcinoma (OSCC), the variables related to diagnostic delay ascribable to the patient, with particular reference to the cognitive and psychological ones. A total of 156 patients with OSCC (mean age: 62 years, M/F: 2.39∶1) were recruited at the Universities of Palermo and Naples. Risk factors related to patient delay included: sociodemographic, health-related, cognitive and psychological variables. The analysis was conducted by considering two different delay ranges: dichotomous (≤1 month vs. >1 month) and polytomous (3 months) delay. Data were investigated…
Rasch scalability of the somatosensory amplification scale: a mixture distribution approach.
2012
Abstract Objective Somatosensory amplification refers to a person's tendency to experience somatic sensations as inappropriately intense and involves hypervigilance concerning bodily sensations. We applied the Somatosensory Amplification Scale (SSAS) in an Internet sample of young adults (N = 3031) to test whether the SSAS is Rasch scalable. Methods We applied mixture distribution extensions of the partial credit and rating scale models to identify possible subgroups that use the response set of the SSAS in different ways. Results A partial credit model, with two latent classes, showed a superior fit to all other models. Still, one of the SSAS items had to be removed because it showed sever…
Dimensionality of depression in acute schizophrenia: a methodological study using the Bech-Rafaelsen Melancholia Scale (BRMES).
1998
Abstract Despite the great clinical importance of depressive symptoms in schizophrenia there is a lack of studies on the assessment and evaluation of depression in acutely psychotic patients. For the Bech-Rafaelsen Melancholia Scale (BRMES), among other advantages, the concept of unidimensionality was confirmed in patients with major depression by different methodological approaches including Rasch analysis. The present evaluation was designed to investigate the scale properties of the BRMES in acutely schizophrenic patients with particular emphasis on the dimensionality of the scale. Three different statistical approaches were used: principal component analysis in combination with computer…
Rasch measurement in educational contexts Special issue 1: Rasch modeling in educational testing
2011
This is the first of two special journal issues on Rasch measurement in educational contexts. Most of the articles compiled in these two issues originate from a symposium of the same title held in ...
Advantages of the Rasch measurement model in analysing educational tests:an applicator's reflection
2011
Educational achievement is a very important issue for parents, teachers, and the government. An accurate measurement plays a very important role in evaluating achievement fairly, and, therefore, analysis methods have been developed considerably in recent years. Education based on long-time learning processes forms a fruitful base for item tests, as it opens up possibilities to design a nearly unlimited number of items. There are several methods available to analyse such tests, but which method is the most useful and in which situation? The Rasch measurement from the Institute for Object Measurement (IOM) has pointed out to be the most useful in evaluating individual items and their function…
L'imputazione dei dati mancanti: l'effetto sui parametri di un Extended Logistic Rasch Model
2008
Il problema dei dati mancanti è abbastanza comune nella ricerca empirica, specialmente nelle scienze sociali in cui il tentativo di misurazione di quantità non direttamente osservabili (variabili latenti)avviene attraverso la somministrazione di test o questionari costituiti da più item. I modelli statistici finalizzati alla soluzione di tale problema richiedono, in genere, un elevato numero di osservazioni per ogni unità coinvolta nell’analisi. In un contesto multivariato il problema si amplifica, poiché nel modello sono considerati più item per ciascuna osservazione: la probabilità, quindi, di avere almeno un dato mancante non è irrilevante ed è, inoltre, crescente al crescere del numero …
Do personal characteristics affect the Rasch measures of perceived physical risk? A quantile regression approach
2012
This paper focuses on the measurement of the perception of healthy risk according to personal characteristics. The Physical Risk Assessment Inventory was adopted as measurement tool and it was administered to 551 students enrolled in the first and in the fifth classes of some high schools of Palermo. The analysis of the determinants of the perceived risk is based on its quantitative measures. Therefore the analysis has been developed into two tracks. First track is devoted to obtain a quantitative measure of the perceived risk: an Extended Logistic Rasch Model was used considering separately males and females. Results highlight the different perception of risk between males and females, alt…
Modeling Ordinal Item Responses via Binary GLMMs and Alternative Link Functions: An Application to Measurement of a Perceived Service Quality
2010
Evaluation of a service on the basis of consumer opinion is a widespread practice in many fields. The assessment of perceived quality [7] of a service is generally carried out through administration of a questionnaire, composed of several items with responses posed on an ordinal scale, whereby each item represents an important feature of the evaluated service [3, 7]. In this context, the aim is to evaluate something similar to the external effectiveness, that is the part of efficacy related to the satisfaction expressed by the service users for the provided service. A particular and important example of service users is represented by students’ responses measuring the perceived quality of s…
Estimating person parameters via item response model and simple sum score in small samples with few polytomous items: A simulation study
2018
Background The Item Response Theory (IRT) is becoming increasingly popular for item analysis. Theoretical considerations and simulation studies suggest that parameter estimates will become precise only by utilizing many items in large samples. Method A simulation study focusing on a single scale was performed on data with (a) n = 40, 60, 80, 120, 200, 300, 500, and 900 cases utilizing (b) 4, 8, 16, or 32 items. The items were (c) symmetrically distributed vs. skew (skewness 0, 1, and 2). Item loadings were (d) homogeneous vs. heterogeneous. Item loadings were (e) low vs. high. Half of the items had (f) a correlated error or not. The number of answering categories (g) was four vs. five. A to…
GLAM ORGANIZATIONS’ DIGITAL MATURITY INDICATOR: A STATISTICAL APPROACH FOR CAMPANIA MUSEUMS
2019
Digital Maturity is a complex phenomenon, involving vertical as well as horizontal processes throughout firms. Therefore, the use of multidimensional tools represents the most appropriate approach in measuring companies’ digital transformation status (Chanias and Hess, 2016). In recent years, Digital Maturity Models (DMMs)were developed in order to get a current measure of an organization’s as-is digital capability (Deloitte, 2018). However, DMMs’ effectiveness relies purely on raw data without taking into account items’ different difficulties. Moreover, though the vast majority of digital maturity models are mainly focused on manufacturing based organizations, an understanding of the chall…