Carla Rampichini

Carla Rampichini
University of Florence | UNIFI · Dipartimento di Statistica, Informatica, Applicazioni "G. Parenti" (DiSIA)

21.51
 · 
PhD
About
68
Research items
18,563
Reads
485
Citations
Research Experience
Jan 1998
Università degli Studi di Firenze
Position
Description
  • Full professor Statistics Main interest: multilevel models, categorical variables, evaluation
Education
Oct 1990 - Dec 1994
University of Florence
Field of study
  • Applied Statistics
Dec 1982 - Dec 1989
University of Florence
Field of study
  • Economics, Statistics
Nov 1979 - Dec 1982
University of Florence
Field of study
  • Statistics
Network
Cited By
Followers
Following
Projects
Project (1)
Project
Omar Paccagnella is the Principal Investigator The general purpose of this project is to enrich the international literature on multilevel modelling along two directions: - investigating theoretical and methodological issues on multilevel extensions of models that analyse bounded outcomes; - applying new methodological results or advanced multilevel solutions to real, hierarchically structured, datasets.
Research
Research items (68)
Chapter
This work focuses on the relationship between student evaluation of teaching and student, teacher and course specific characteristics, exploiting the richness of information collected by a new survey carried out among professors of the University of Padua. Data collected in this survey are able to highlight teacher needs, beliefs and practices of t...
Article
In this note we briefly discuss the structure of CUB models and their interpretation. Furthermore, we elaborate some issues related to the comparison of CUB models with mainstream approaches, focusing on generalized linear models for univariate ordinal responses and classical latent variable models for multivariate ordinal responses. full-text view...
Preprint
Full-text available
The paper is motivated by the analysis of the relationship between ratings and teacher practices and beliefs, which are measured via a set of binary and ordinal items collected by a specific survey with nearly half missing respondents. The analysis, which is based on a two-level random effect model, must face two about the items measuring teacher p...
Article
Full-text available
Multilevel models are a key tool for the analysis of clustered data in a wide range of fields. The paper discusses a handful of critical choices in multilevel modelling. Some choices are peculiar of the multilevel setting, like the specification of the multilevel structure of the model, cluster-mean centering of the covariates, fixed versus random...
Article
Licenza d'uso L'articolò e messo a disposizione dell'utente in licenza per uso esclusivamente privato e personale, senza scopo di lucro e senza fini direttamente o indirettamente commerciali. Salvo quanto espressamente previsto dalla licenza d'uso Rivisteweb, ` e fatto divieto di riprodurre, trasmettere, distribuire o altrimenti utilizzare l'artico...
Chapter
This work is motivated by a study on aging based on a representative population living in the Chianti geographic area (Tuscany, Italy). Multiple factors may influence the ability to walk, and no standard criteria are currently available to establish whether these factors are functioning within the “normal” range. Our work exploits data collected du...
Article
Full-text available
In certain academic systems, a student can enroll for an exam immediately after the end of the teaching period or can postpone it to any later examination session, so that the grade is missing until the exam is not attempted. We propose an approach for the evaluation in itinere of a student's proficiency accounting also for non-attempted exams. The...
Poster
Full-text available
In times of scarcity of resources and high employment levels, training programs typically do not have sufficient resources to serve all those who require re-skilling. In this context an accurate selection of unemployment into programs is crucial for distributional equity and economic efficiency. In Italy, only recently reforms in the field of activ...
Data
We illustrate how to perform a multivariate multilevel analysis in the complex setting of large-scale assessment surveys, dealing with plausible values and accounting for the survey design. In particular, we consider the Italian sample of the TIMSS&PIRLS 2011 Combined International Database on fourth grade students. The multivariate approach jointl...
Article
Background : In 2010, Tuscany (Italy) implemented the Chronic Care Model (CCM), to improve general practitioner (GP) management of chronic diseases. Aim : assessing how the introduction of CCM affected GPs’ compliance with standards of care for diabetes patients. Methods : A controlled before-after study was performed. Two exposed groups of GPs,...
Article
Full-text available
The paper is Open Access on The Annals of Applied Statistics: http://projecteuclid.org/euclid.aoas/1483606865 We exploit a multivariate multilevel model for the analysis of the Italian sample of the TIMSS\&PIRLS 2011 Combined International Database on fourth grade students. The multivariate approach jointly considers educational achievement on Read...
Article
Full-text available
Considering the case of the School of Economics of the University of Florence, the paper investigates whether the pre-enrolment assessment test is an effective tool to predict student performance. The analysis is tailored to evaluate the additional information yielded by the test beyond the background characteristics of the candidates already avail...
Article
Full-text available
The analysis of highly structured data requires models with unobserved components (random effects) able to adequately account for the patterns of variances and correlations. The specification of the unobserved components is a key and challenging task. In this paper, we first review the literature about the consequences of misspecifying the distribu...
Article
Full-text available
The papers in this section are based on presentations from the international conference of the Italian Statistical Society (SIS) “Advances in Latent Variables: Methods, Models and Applications”. The conference was held in Brescia, Italy, on June 19-21, 2013, and included talks, posters, and symposia on topics related to the latent variable approach...
Article
Full-text available
In multilevel models for binary responses, estimation is computationally challenging due to the need to evaluate intractable integrals. In this paper, we investigate the performance of integrated nested Laplace approximation (INLA), a fast deterministic method for Bayesian inference. In particular, we conduct an xtensive simulation study to compare...
Article
Full-text available
[SharedIt link to the full text: http://rdcu.be/nK5p] The paper proposes a latent class version of Combination of Uniform and (shifted) Binomial random variables ( CUB ) models for ordinal data to account for unobserved heterogeneity. The extension, called LC-CUB , is useful when the heterogeneity is originated by clusters of respondents not identi...
Chapter
Full-text available
Encyclopedia entry with an overview of ordered logit models
Article
Full-text available
The paper focuses on the analysis of the performance of university students, with reference to first year compulsory courses. The main goal is to compare the exams in terms of difficulty, discrimination and use of the grades. Moreover, the paper aims at assessing how student careers depend on student and course characteristics. The analysis exploit...
Article
In family medicine contrasting evidence exists on the effectiveness of team practice compared with solo practice on chronic disease management. In Italy, several experiences of team practice have been introduced since the late 1990s but few studies detail their impact on the quality of care. The aim of this paper is to evaluate the impact of team p...
Article
Full-text available
The paper reviews finite mixture models for binomial counts with concomitant variables. These models are well known in theory, but they are rarely applied. We use a binomial finite mixture to model the number of credits gained by freshmen during the first year at the School of Economics of the University of Florence. The finite mixture approach al...
Article
Standard asymptotic chi-square distribution of the likelihood ratio and score statistics under the null hypothesis does not hold when the parameter value is on the boundary of the parameter space. In mixed models it is of interest to test for a zero random effect variance component. Some available tests for the variance component are reviewed and a...
Article
The paper evaluates the effects of Italian university grants on student dropout. Eligible applicants receive a grant if their family economic indicator is below a specified threshold, so the grant assignment rule appeals to a regression discontinuity design. After a brief introduction to regression discontinuity designs, the particular setting that...
Article
In the academic year 2008/2009, the School of Economics of the University of Florence introduced a compulsory test to evaluate the background of the students wishing to enrol in a degree program. In this paper, we assess the predictive power of the test score in terms of number of gained credits, making comparisons with the predictive power of vari...
Chapter
This chapter is devoted to regression models for ordinal responses with special emphasis on random effects models for multilevel or clustered data. After a brief discussion on ordinal variables in the first section, the second section reviews the most common regression models for ordinal responses focusing on cumulative models, namely models based...
Article
Full-text available
The paper explores some issues related to endogeneity in multilevel models, focusing on the case where the random effects are correlated with a level 1 covariate in a linear random intercept model. We consider two basic specifications, without and with the sample cluster mean. It is generally acknowledged that the omission of the cluster mean may c...
Article
Full-text available
This paper aims at measuring the external effectiveness of the degree programmes of Italian universities taking into account both the characteristics of graduates and some context factors that differently affect the Italian regional labour markets. The analysis is performed via a multilevel logistic model using the Istat survey on Italian graduates...
Article
Full-text available
SharedIt link to full text: http://rdcu.be/nPeo The paper investigates the consequences of sample selection in multilevel or mixed models, focusing on the random intercept two-level linear model under a selection mechanism acting at both hierarchical levels. The behavior of sample selection and the resulting biases on the regression coef- ficients...
Chapter
Full-text available
The methodology for the evaluation of educational systems is being developed in different fields, such as educational statistics, psychometrics, sociology and econometrics. Each discipline has developed approaches suitable for the analysis of particular aspects of the evaluation process. For example, educational statistics focuses on learning curve...
Article
Full-text available
In the paper we show how the well-known principle of variance decomposition within and between groups can be extended to the case of a specific dispersion index for ordinal variables.
Article
In this paper, we propose a way to incorporate multilevel models within graphical models. We introduce three types of nodes for chain graphs to represent (1) individual within clusters, (2) clusters as latent variables and (3) interactive effects. In this way, the chain graph shows both the associations among individuals introduced by clusters and...
Article
Full-text available
SharedIt link to full text: http://rdcu.be/nPeT The main goal of the paper is to specify a suitable multivariate multilevel model for polytomous responses with a non-ignorable missing data mechanism in order to determine the factors which influence the way of acquisition of the skills of the graduates and to evaluate the degree programmes on the ba...
Article
Full-text available
The paper tackles several issues involved in specifying, fitting and interpreting the results of multilevel factor models for ordinal variables. First, the problem of model specification and identification is addressed, outlining the parameter interpretation. Special attention is devoted to the consequences on interpretation stemming from the usual...
Article
Full-text available
In this paper, we analyse some aspects of job satisfaction by means of a multilevel factor model, decomposing the factor structure into the graduate and degree programme components, using data from a survey on the 1998 graduates of the University of Florence. Due to the ordinal scale of the response variables, we adopt a multilevel factor model for...
Chapter
Full-text available
The main goal of the present paper is the analysis of the working position of graduates using multilevel and chain graph models, extended to the case of correlated data. After a brief introduction to multilevel modelling and a description of the conditional independence implied by the model, we describe chain graphs for multilevel models. The model...
Article
Full-text available
We outline how to use the Stata command 'gllamm' to fit several random effects models, including continuous, binary, ordered, unordered and count responses, bivariate normal-binary responses, and meta-analysis.
Article
Full-text available
The paper explores the issue of endogeneity in random effects models, focusing on the case where the random effects are correlated with a level 1 covariate in a simple linear random intercept model. This type of endogeneity arises from a wrong equality restriction on the between-cluster and within-cluster slopes. We show that estimation of the betw...
Article
In the paper we present a comprehensive methodology for the analysis of student ratings of university courses. First, simple descriptive measures, which take into account the ordinal nature of the ratings, are discussed. Then net measures, which adjust for the characteristics of the students, are obtained through multilevel modelling. Finally, the...
Article
Full-text available
Multivariate multilevel models for ordinal variables are quite complex with respect to both interpretation and estimation. The specification in terms of a multivariate latent distribution and a set of thresholds helps in the interpretation of the variance-covariance parameters. However, most existing estimation algorithms for multilevel models can...
Article
Full-text available
The paper presents some criteria for the specification of ordinal variance component models when the units are grouped in a limited number of strata. The base model is specified using a latent variable approach, allowing the first level variance, the second level variance and the thresholds to vary according to the strata. However this model is not...
Article
La valutazione di efficacia delle borse di studio in Toscana (di Gianni Aristelli, Carla Rampichini e Nicola Sciclone) - ABSTRACT: The paper deals with the impact evaluation of university scholarships financed by the Tuscany Region during the last years. The data sets collecting the individual data of all the students from the three Tuscany univers...
Article
Full-text available
Logit models with random effects are now widely used in applied Statistics and Econometrics. They usually lead to intractable likelihood functions, as they involve integrals without closed form solution. Numerical integration can be used to compute the likelihood and software is available (Hedeker and Gibbons, 1996). Difficulties can be encountered...
Article
Non-normal multilevel models usually lead to intractable likelihood functions, as they involve integrals without closed-form solution. A flexible approach for their estimation consists in replacing the initial model with an approximated one which is easier to handle, as the quasi-likelihood method with a linearising transformation proposed by Golds...
Article
The aim of this paper is to study the individual and contextual determinants of life satisfaction in Italy. A hierarchical probit model is proposed for studying data with group structure and an ordinal response variable. The group structure is defined by the presence of micro observations embedded with regional contexts (macro observations), and th...
Article
Full-text available
The paper tackles the problem of identification of treatment effects in a regression-discontinuity-design (RDD) in the presence of heterogeneous effects. A RDD allows identification of average treatment effects only f or a subset of individuals around the threshold for the participation status. The pape r shows how a sharp RDD may provide: a) addit...
Article
Full-text available
This contribution presents a methodology for the analysis of student ratings of university courses. Student ratings are an old and widely recognized instrument to evaluate university courses (Emerson, 2000). However the statistical analysis of student ratings need special techniques which take into account: (i) the ordinal nature of the ratings, (i...
Article
Abbiamo detto chepù o essere utile ruotare il sistema di coordinate di un certo angolo θ per cercare una migliore interpretazione dei fattori. In parti-colare, mostreremo che scegliendo una rotazione opportuna psipù o ottenere una matrice dei factor loadings LTpì u semplice da interpretare. I loadings rappresentano le covarianze (correlazioni) tra...
Article
Full-text available
The University of Florence (Italy) offers some scholarships every year to eligible freshmen: eligibility is based on merit and economic needs. The number of grants awarded is usually constrained by a fixed budget: not all students applying for a grant receive one. Applicants are ranked on the basis of an economic indicator, that depends in a determ...