13 research outputs found
A novel CFA+EFA model to detect aberrant respondents
Aberrant respondents are common but yet extremely detrimental to the quality
of social surveys or questionnaires. Recently, factor mixture models have been
employed to identify individuals providing deceptive or careless responses. We
propose a comprehensive factor mixture model that combines confirmatory and
exploratory factor models to represent both the non-aberrant and aberrant
components of the responses. The flexibility of the proposed solution allows
for the identification of two of the most common aberant response styles,
namely faking and careless responding. We validated our approach by means of
two simulations and two case studies. The results indicate the effectiveness of
the proposed model in handling with aberrant responses in social and behavioral
surveys.Comment: 24 pages, 5 figures, 7 table
A psychometric modeling approach to fuzzy rating data
Modeling fuzziness and imprecision in human rating data is a crucial problem
in many research areas, including applied statistics, behavioral, social, and
health sciences. Because of the interplay between cognitive, affective, and
contextual factors, the process of answering survey questions is a complex
task, which can barely be captured by standard (crisp) rating responses. Fuzzy
rating scales have progressively been adopted to overcome some of the
limitations of standard rating scales, including their inability to disentangle
decision uncertainty from individual responses. The aim of this article is to
provide a novel fuzzy scaling procedure which uses Item Response Theory trees
(IRTrees) as a psychometric model for the stage-wise latent response process.
In so doing, fuzziness of rating data is modeled using the overall rater's
pattern of responses instead of being computed using a single-item based
approach. This offers a consistent system for interpreting fuzziness in terms
of individual-based decision uncertainty. A simulation study and two empirical
applications are adopted to assess the characteristics of the proposed model
and provide converging results about its effectiveness in modeling fuzziness
and imprecision in rating data
Results from the Cuore Experiment
The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double beta decay that has been able to reach the 1-ton scale. The detector consists of an array of 988 TeO2 crystals arranged in a cylindrical compact structure of 19 towers, each of them made of 52 crystals. The construction of the experiment was completed in August 2016 and the data taking started in spring 2017 after a period of commissioning and tests. In this work we present the neutrinoless double beta decay results of CUORE from examining a total TeO2 exposure of 86.3kg yr, characterized by an effective energy resolution of 7.7 keV FWHM and a background in the region of interest of 0.014 counts/ (keV kg yr). In this physics run, CUORE placed a lower limit on the decay half- life of neutrinoless double beta decay of 130Te > 1.3.1025 yr (90% C. L.). Moreover, an analysis of the background of the experiment is presented as well as the measurement of the 130Te 2vo3p decay with a resulting half- life of T2 2. [7.9 :- 0.1 (stat.) :- 0.2 (syst.)] x 10(20) yr which is the most precise measurement of the half- life and compatible with previous results
Jointly Modeling Rating Responses and Times with Fuzzy Numbers: An Application to Psychometric Data
In several research areas, ratings data and response times have been successfully used to unfold the stagewise process through which human raters provide their responses to questionnaires and social surveys. A limitation of the standard approach to analyze this type of data is that it requires the use of independent statistical models. Although this provides an effective way to simplify the data analysis, it could potentially involve difficulties with regard to statistical inference and interpretation. In this sense, a joint analysis could be more effective. In this research article, we describe a way to jointly analyze ratings and response times by means of fuzzy numbers. A probabilistic tree model framework has been adopted to fuzzify ratings data and four-parameters triangular fuzzy numbers have been used in order to integrate crisp responses and times. Finally, a real case study on psychometric data is discussed in order to illustrate the proposed methodology. Overall, we provide initial findings to the problem of using fuzzy numbers as abstract models for representing ratings data with additional information (i.e., response times). The results indicate that using fuzzy numbers leads to theoretically sound and more parsimonious data analysis methods, which limit some statistical issues that may occur with standard data analysis procedures
Twitting about COVID-19: An application of Structural Topic Models to a sample of Italian tweets
During the COVID-19 pandemic, vaccination emerged as a burning issue in the Italian public discussion. In particular, social media were an important vehicle for spreading news, information, and opinions, both true and false, regarding health. In this contribution, we present an application of Structural Topic Model (STM) to a tweets-based corpus concerning the Italian public debate about COVID-19 vaccines. The aim is to detect the evolution of tweets-related topics characterizing the Italian public opinion about COVID-19 vaccination