1,721,228 research outputs found
Induzioni
No full textLa rivista è rivolta agli studenti ed ai docenti di matematica, storia, geografia, osservazioni scientifiche, economia, statistica ... delle scuole preuniversitarie, ma anche ai docenti universitari. Il suo scopo è quello di diffondere idee statistiche nella scuola e di illustrare attraverso esempi come la statistica possa essere di ausilio in diverse occasioni della vita pratica
Investigating the Judges Performance in a National Competition of Sport Dance
Full text linkMany sports, such as gymnastics, diving, figure skating, etc. use judges’ scores to generate a rank for determining the winner of a competition. These judges use some type of rating scale when assessing performances. Human ratings are subject to various forms of error and bias. The overall outcomes may largely depend upon the set of chosen raters. The aim of this paper is to illustrate how results from the Many-Facet Rasch Measurement framework can be used to highlight feedback to judges about their scoring patterns. The purpose is to analytically detect anomalous rater behaviours. We consider the field of Sport Dance, a discipline which enjoys increasing public interest and passion in recent years. We analyze data relating to two national competitions held in Italy in 2018 and 2019
A Bayesian multidimensional IRT approach for the analysis of residents’ perceptions toward tourism
Full text linkIn this study, a Bayesian multidimensonal item response theory (IRT) model assuming the presence of correlated general and specific latent traits is proposed for the investigation of residents' perceptions toward the tourism industry. Data collected in 2012 in the Italian Romagna area were used to study the perceived benefits and costs related to tourism. By using posterior predictive model checks and Bayesian deviance, the additive IRT model was found to fit the data well. More importantly, the results could be interpreted meaningfully, showing the most and least important perceived advantages and disadvantages of tourism for the local community. Finally, thanks to the compensatory structure of the model, the different influence of the overall attitude and the specific perceptions of the respondents could be investigated for each aspect included in the questionnaire
Assessing maths learning gaps using Italian longitudinal data
Full text linkIn the educational context, one of the main goals is to reduce the disparities among students, generally at the national level, to allow all individuals to achieve a similar cultural background. Using data from a large-scale standardised test administered by INVALSI (National Institute for the Evaluation of the Educational System), this paper offers a first longitudinal analysis of the performance in the maths test of a cohort of students enrolled in 2013/2014 at grade 8 and observed up to grade 13. The aim is to identify those obstacles that undermine students’ learning to help them adopt informed educational actions. Specific features of these data are their hierarchical structure and the presence of not vertically scaled scores. Two approaches have been followed for their analysis: growth models and growth percentiles. Coherently with the literature, our results suggest the presence of a gender gap and a significant impact on the type of school and social-cultural background. Unlike previous research on the INVALSI data, we evaluate these time-invariant covariates’ effects on students’ performance over different school cycles
Dealing with uncertainty in automated test assembly problems
No full textIl recente sviluppo delle tecnologie informatiche ha consentito agli istituti di valutazione di migliorare il processo di assemblaggio dei test tramite l’automated test assembly (ATA). Una struttura generale per ATA consiste nell’adottare modelli di programmazione intera-mista. Questi modelli sono pensati per essere risolti dasolver commerciali che, nonostante il loro successo nella gestione della maggiorparte dei problemi noti, non sono sempre in grado di risolvere problemi di ATA molto vincolati o di grandi dimensioni. Inoltre, tutti i parametri sono considerati fissi e noti, un’ipotesi che non vale per le stime dei parametri di item response theory (IRT). In questo lavoro proponiamo un modello chance-constrained per affrontarel’incertezza nei modelli di ATA senza aumentarne la complessitàThe recent development of computer technologies enabled test institutes to improve the test assembly process by automated test assembly (ATA). A general framework for ATA consists in adopting mixed-integer programming models. These models are intended to be solved by common commercial solvers which, notwithstanding their success in handling most of the known problems, are not always able to find solutions for highly constrained and large-sized ATA problems. Moreover, all parameters are assumed to be fixed and known, a hypothesis that is not true for estimates of item response theory (IRT) parameters. In this work, we propose a chance-constrained model for dealing with uncertainty in ATA without increasing the complexity of the model
A Latent Curve Analysis Of Unobserved Heterogeneity In University Achievements
Full text linkThis paper analyses the academic achievement of a cohort of students enrolled in 2001 at the Faculty of Economics of the University of Bologna by using a latent growth model for longitudinal data. The basic idea of this approach is that individuals differ in their growth over time according to a continuous underlying or latent trajectory. Random coefficients in the model allow each individual to have a different trajectory. La- tent growth models can be incorporated into the Structural Equation Models (SEMs) framework by viewing the random coefficients as latent variables. Hence model identification and estimation are performed according to the conventions of the SEM analysis. The effects of different covariates on the student temporal behaviour is also evaluated
Multidimensional IRT models to analyze learning outcomes of Italian students at the end of lower secondary school
No full textIn this paper, different multidimensional IRT models are compared in order to choose the best approach to explain response data on Italian student assessment at the end of lower secondary school. The results show that the additive model with three specific dimensions (reading comprehension, grammar, and mathematics abilities) and an overall ability is able to recover the test structure meaningfully. In this model, the overall ability compensates for the specific ability (or vice versa) in order to determine the probability of a correct response. Given the item characteristics, the overall ability is interpreted as a reasoning and thinking capability. Model estimation is conducted via Gibbs sampler within a Bayesian approach, which allows the use of Bayesian model comparison techniques such as posterior predictive model checking for model comparison and fit
Un indicatore statistico del background familiare nello studio del successo scolastico degli studenti nella provincia di Bologna
No full textIn questo lavoro viene presentata una proposta metodologica per la costruzione di indicatore statistico dello status socio culturale delle famiglie con riferimento ai dati di un’indagine dell’Osservatorio sulla scolarità della Provincia di Bologna sugli esiti scolastici di un campione di studenti della scuola secondaria di II grado. Dalle analisi condotte emerge l’esistenza di un legame tra retroterra familiare e risultato scolastico. Nemmeno in una realtà ad alta scolarità, quale quella bolognese la scuola sembra essere in grado di neutralizzare l’effetto di ambientii familiari sfavorevoli sul rendimento scolastico dei ragazzi
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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