Sensitivity Analysis of Composite Indicators through Mixed Model Anova

The paper proposes a new approach for analysing the stability of Composite Indicators. Starting from the consideration that different subjective choices occur in their construction, the paper emphasizes the importance of investigating the possible alternatives in order to have a clear and objective picture of the phenomenon under investigation. Methods dealing with Composite Indicator stability are known in literature as Sensitivity Analysis. In such a framework, the paper presents a new approach based on a combination of explorative and confirmative analysis aiming to investigate the impact of the different subjective choices on the Composite Indicator variability and the related individual differences among the statistical units as well.sensitivity analysis,composite indicators,analysis of variance,principal component analysis

The use of analysis of variance and three-way factor analysis methods for studying the quality of a sensory panel

In sensory analysis a panel of assessors evaluate a collection of samples/products with respect to a number of sensory characteristics. Assessments are collected in a threeway data matrix crossing products, attributes and assessors. The main objective of the experiment is to evaluate products. However, the performance of each assessor and of the panel as a whole is of crucial importance for a successful analysis. At this aim univariate analysis for each sensory attribute as well as multi-way analysis considering all directions of information are usually performed. The present work studies the quality of a panel using both methods. The basic idea is to compare results and investigate relations between the two different analytical approaches

Panel performance: Modelling variation in sensory profiling data by multiway analysis

Sensory profiling data is essentially three-way data where samples, attributes and assessors are the three dimensions of information. It is common practice to average over the assessors and focus the analysis on the relations between samples and sensory descriptors. However, since assessor reliability can not be controlled in advance, posthoc analysis on assessors is needed to assess performance of the individual and at the panel level. For this purpose, multiway analysis is a very efficient data method as it provides information on samples, attributes and assessors, simultaneously [1]. PARAllel FACtor (PARAFAC) analysis is one of the most used multiway methods in sensory analysis [2][3]. It is based on two basic assumptions: 1) there exist latent variables behind the identified sensory descriptors describing the variation among the products; 2) assessors have different sensitivities to these common latent variables. However, assessors may perceive the factors differently, so the assumption of “common latent variables” becomes questionable. This may happen when the panel is not well trained and/or the samples present subtle differences difficult to detect. In this work a more flexible approach to the analysis of sensory data is presented. Specifically, the work proposes to use PARAFAC2 modelling [4] as it allows each assessor to have an individual idiosyncratic perceptive model. The data was obtained from a descriptive sensory analysis of organic milk samples. Results show that PARAFAC2 is very useful to highlight disagreement in the panel on specific attributes and to detect outlying assessors. In addition, by using PARAFAC2 an improvement in the description of samples is also achieved. On the other hand, PARAFAC has to be preferred to PARAFAC2 when a good panel agreement is observed, since it provides more stable solutions and no further gain in information is obtained from PARAFAC2. Finally, the work proposes an index to measure the performance of each assessor based on individual sensitivity and reproducibility

Pedagogical Intervention Research for Cultural Integration and Inclusion : Reflections on Mixed and Multiple Methodologies

The present paper aims to offer a new perspective trough which to study the current phenomena of decolonization and crossbreeding. It will be discussed particularly the theoretical perspective of intercultural approach (Hannoun H., 1987) [1], in order to deconstruct the historical approaches to the dynamics of immigration and meeting of different cultures (Neto F., 2002; Montreuil A., 2004) [2]. The traditional approaches were based on the analysis of the processes of “assimilation” or “acculturation” of the minority culture (Bourhis R.Y., 2007, Barry J.W., 1997) [3], but always from the point of view of the ethnocentric vision. The paper wants also to argue how to re-think intercultural pedagogical research epistemologies and methodologies according to the paradigm of complexity and of methodological pluralism, to avoid proposing the cross-cultural comparison “the West vs the Rest”(Baldacci M., 2012) [4]. The research interest is to bring to light the richness and the depth of the meeting and the exchange between participants who come from different ethnic and cultural horizons, and to grasp the social and community impact of the co-constructed knowledge thanks to the research (Mantovani G., 2008) [5]. Moreover, one of the principal guidelines for the scientific research contained in the plane of Horizon 2020, seems to be that of “Inclusive, innovative and Safe Societies” (Horizon 2020, 2013): it needs to keep in mind criteria of usefulness (Armezzani M., 2004) [6] and of usability of the products of intercultural research, also to meet international standards. It will be presented, then, an intervention-research carried out in the working realities where participants coming from other cultures and nations are employed. It is an action-research aimed to assume participants’ points of view, to capture specific learning needs, to give voice to these specific formative instances and, through which and with which, to design possible plans of intervention to answer to these educational needs

Monitoring panel performance within and between sensory experiments by multi-way analysis

In sensory analysis a panel of trained assessors evaluates a set of samples according to specific sensory descriptors. The training improves objectivity and reliability of assessments. However, there can be individual differences between assessors left after the training that should be taken into account in the analysis. Monitoring panel performance is then crucial for optimal sensory evaluations. The quality of the results is strongly dependent on the performance of each assessor and of the panel as a whole. The present work proposes to analyze the panel performance within single sensory evaluations and between consecutive evaluations. The basic idea is to use multi-way models to handle the three-way nature of the sensory data. Specifically, a PARAFAC model is used to investigate the panel performance in the single experiment. N-PLS model is used to test the predictive ability of the panel on each experiment. A PARAFAC model is also used for monitoring panel performance over different experiments

On the use of quantile regression to deal with heterogeneity: the case of multi-block data

AbstractThe aim of the paper is to propose a quantile regression based strategy to assess heterogeneity in a multi-block type data structure. Specifically, the paper deals with a particular data structure where several blocks of variables are observed on the same units and a structure of relations is assumed between the different blocks. The idea is that quantile regression complements the results of the least squares regression by evaluating the impact of regressors on the entire distribution of the dependent variable, and not only exclusively on the expected value. By taking advantage of this, the proposed approach analyses the relationship among a dependent variable block and a set of regressors blocks but highlighting possible similarities among the statistical units. An empirical analysis is provided in the consumer analysis framework with the aim to cluster groups of consumers according to the similarities in the dependence structure among their overall liking and the liking for different drivers

A hybrid approach for the analysis of complex categorical data structures: assessment of latent distance learning perception in higher education

A long tradition of analysing ordinal response data deals with parametric models, which started with the seminal approach of cumulative models. When data are collected by means of Likert scale survey questions in which several scored items measure one or more latent traits, one of the sore topics is how to deal with the ordered categories. A stacked ensemble (or hybrid) model is introduced in the proposal to tackle the limitations of summing up the items. In particular, multiple items responses are synthesised into a single meta-item, defined via a joint data reduction approach; the meta-item is then modelled according to regression approaches for ordered polytomous variables accounting for potential scaling effects. Finally, a recursive partitioning method yielding trees provides automatic variable selection. The performance of the method is evaluated empirically by using a survey on Distance Learning perception

An eighteen-month follow-up study on the effects of intravitreal dexamethasone implant in diabetic macular edema refractory to anti-VEGF therapy

Abstract AIM: To evaluate the long-term efficacy and safety of dexamethasone implants in subjects affected by diabetic macular edema (DME) resistant to anti-vascular endothelial growth factor (VEGF) therapy. METHODS: Thirty-two DME patients were enrolled. A 700 microgram slow release Intravitreal Dexamethasone Implant (Ozurdex®) was placed in the vitreous cavity. All patients were followed for 18mo. Best-corrected visual acuity (BCVA) measured with Early Treatment Diabetic Retinopathy Study (ETDRS) and central macular thickness (CMT) exams were carried out at baseline (T0) and after 1 (T1), 3 (T3), 4 (T4), 6 (T6), 9 (T9), 12 (T12), 15 (T15), and 18mo (T18) post injection. RESULTS: Repeated measures ANOVA showed an effect of treatment on ETDRS (P<0.0001). Post hoc analyses revealed that ETDRS values were significantly increased at T1, T3, T4, T9, and T15 (P<0.001) as compared to baseline value (T0). At T6, T12, and T18, ETDRS values were still statistically higher than baseline (P<0.001 vs T0). However, at these time points, we observed a trend to return to baseline conditions. ANOVA also showed an effect of treatment (P<0.0001). CMT decreased significantly at T1, T3, T4, T9, and T15 (P<0.001). At T6 (P<0.01), T12 and T18 (P<0.001) CMT was also significantly lower than T0 although a trend to return to the baseline conditions was also observed. CONCLUSION: Our findings demonstrate that Intravitreal Dexamethasone Implant is a good option to improve BCVA and CMT in DME patients resistant to anti-VEGF therapy. Our data also show that the use of drugs administered directly into the vitreous allows achieving appropriate and long-lasting concentration at the site of disease without systemic side effects

Surveys as Praxis: A Pilot Study on Transformative Learning Assessment with the Laboratory Experience of the Theatre of the Oppressed

Transformative learning has been important in the development of college and adult education since Jack Mezirow proposed it more than 40 years ago as a theoretical description of the steps learners undergo in changing their worldviews. From the educator’s perspective, transformative learning is when a learner is struck by a new concept or way of thinking and then follows through to make a life change; it supplements more common types of learning such as acquiring facts or learning new skills (Cranton, 2006) [1]. Little quantitative study has been made of the incidence of transformative learning or the ten steps predicted by Mezirow to precede it (Taylor, 2007) [2]. More European involvement in research on transformative learning is needed, given that the theory of transformative learning does not have concrete roots in the conceptual formation of the European adult educators (Kokkos, 2012) [3]. European adult educators’ rich scholarship on the social and critical dimensions of adult learning (Bourdieu, Foucault, Mayo) would have much to offer the study of transformative learning theory (Taylor & Cranton, 2013) [4]. The real innovation could be the reintegration of the transformative learning with ideas, theories and methodologies of freirerian pedagogy and of democratic adult education, such as Theatre of Oppressed and Forum Theatre, derived from the theory of Augusto Boal (2005) [5]. Our purpose is to create a collaborative international research to study the processes of transformative learning occurring during university laboratory experiences based on Freire’s pedagogical tools and on Boal’s Forum Theatre and Theatre of the Oppressed with graduating students. This paper presents the international pilot study for the validation of the instrument for assessment of the transformative learning adopting the perspective of the theory of ten precursor steps (Taylor, 2007; Brock, 2011) [6]

Artificial Stone Associated Silicosis: A Systematic Review

Silicosis is a progressive fibrotic lung disease that is caused by the inhalation of respirable crystalline silica. Due to its high silica content, artificial stone (AS) can become a possible source of hazardous dust exposure for workers that are employed in the manufacturing, finishing, and installing of AS countertops. Therefore, the aim of this review was to verify the association between AS derived silica exposure and silicosis development, and also then define the pathological characteristics of the disease in relation to specific work practices and preventive and protective measures that were adopted in the workplace. A systematic review of articles available on Pubmed, Scopus, and Isi Web of Knowledge databases was performed. Although the characteristics of AS-associated silicosis were comparable to those that were reported for the disease in traditional silica exposure settings, some critical issues emerged concerning the general lack of suitable strategies for assessing/managing silica risks in these innovative occupational fields. Further research that is designed to assess the hazardous properties of AS dusts, levels of exposure in workplaces, and the effectiveness of protective equipment appears to be needed to increase awareness concerning AS risks and induce employers, employees, and all factory figures that are engaged in prevention to take action to define/adopt proper measures to protect the health of exposed workers