1 Con il patrocinio di Toulon-Verona Conference Università degli studi di Bari Aldo Moro Università degli studi di Foggia Politecnico di Bari Conference on Choice and preference analysis for quality improvement and seminar on experimentation University of Bari University Hall and Student Center (former Palazzo delle Poste ) 9-10 July 2015 BOOK OF ABSTRACTS 2015
2 Stampato: luglio 2015 ISBN Copyright 2015 by Università degli Studi di Bari Aldo Moro Tutti i diritti di traduzione, riproduzione e adattamento, totale o parziale, con qualsiasi mezzo (comprese le copie fotostatiche e i microfilm) sono riservati
3 3 SUMMARY ZAVARRONE E., GRASSIA G., VITAGLIANO M. Photo fooding: Some remarks on measurement processes...p. 5 SANTARCANGELO V., BUONDONNO A., ODDO G., STAFFIERI F.P., SANTARCANGELO N., MARAGNO M., TRENTINELLA F. Web misinformation: A text-mining approach for legal accepted facts...6 TOMA E., D UGGENTO A.M., RICCI V. Factorial analysis of end-to-end performance evaluation of Italian higher education institutions...7 PISCITELLI A., D AMBROSIO A. Sensory evaluation of seven white wines to define consumers preference by key intrinsic attributes to wine choice...8 BOLZAN M., MAROZZI M. Issues in designing an index of trust for public institutions...9 MARIANI P., ZAVANELLA B. Business enterprises and economic system: subjective expectations...10 D ALESSANDRO M.T, GAUDIANO G., COLUCCI M., SANTARCANGELO V., ROMANO A, MINERVA T. Process mining: Review and a case study...11 FABBRIS L., SCIONI M. A fractional design to elicit graduates' preferences for job characteristics...12 FABBRIS L., RAPISARDA L., SCIONI M. An experiment to define the optimum salary for fresh graduates...13 MANDARANO A., TRETTEL A. Misurare il comportamento istintivo durante la fruizione di messaggi pubblicitari, logo aziendale e navigazione internet con la rilevazione dell attività cerebrale, emozionale e di puntamento dello sguardo: il caso di Telecom Italia/TIM...14 DEGAN L., GUIDETTI C., MORICHI M. Analysis and implementation of a NPS (Net Promoter Score) Survey: The Ariston Thermo case...15 GIORDANO G., LAURO C.N., SCEPI G. Embedding covariates in conjoint analysis models...16 GALASSO R., GRASSIA F., GRASSIA M.G., ZAVARRONE E. PLS path modelling for the evaluation of patients' satisfaction of a department...17
4 4 MARIANI, P., RANCATI, E., GORDINI, N. Determinants of student satisfaction in higher education: The case of Bicocca University of Milan...18 ZANELLA A., CASCINI E. Quality control of perishable goods sale points...19 D ANGELLA A., LUPO N., CONTINI D. Mapping di impianti elettrici e tecnologici: misura della qualità per servizi di installazione e manutenzione...20 PALAZZO L., SALVATI D.B., RAGOZINI G. Comparing operative units in a large company through archetypes in a benchmarking perspective...21 SCOLORATO C., SANTELLI F., RAGOZINI G. Understanding customer satisfaction determinants through models for ordinal data...22 LIBERATI C., MARIANI P. Visualization and monitoring of dynamic customer satisfaction...23 MASSARI A., PERCHINUNNO P., GIRONE F. Statistical models for categorical variables for measuring student satisfaction at the University of Bari...24 D UGGENTO A.M., NISIO A. Introducing performance management in universities. The case of the University Aldo Moro of Bari...25 CASCINI E., FACCINI P. Statistica e ricerca industriale: ottimizzazione simultanea delle caratteristiche di un catalizzatore Ziegler-Natta...26 CASCINI E. Ordinamento degli score derivanti dall analisi delle componenti principali mediante un indicatore di qualità complessivo...27 SANTARCANGELO V., ODDO G., PILATO M., VALENTI F., FORNARO C. An opinion mining application on OSINT for a reputation analysis of public administrations...28
5 5 Photo fooding: Some remarks on measurement processes ZAVARRONE E.*, GRASSIA G. **, VITAGLIANO M.* *IULM University of Milan, **University Federico II of Naples Some apps, developed for monitoring the healthy food habit, are based on systems that measure calories and nutrition in meals. Typically the apps user takes a photo (through i.e. smartphone) of the plate and could have an estimate of consumption of calorie and nutritional facts components (Pouladzadeh et al., 2013) in real time. These apps come from recent studies on food habits based on the use of digitalization as alternative to the classic PAPI questionnaire. The food digitalization presents advantages as low level impact and the speed of data acquisition but some limits too. For the digitalization measurement, any formal guidelines or protocol has not been proposed and the proprieties as validity and reliability risk being neglected. Scholars (Gemming et al., 2015, Martin et al. 2014) recognize this limit and they have highlighted some cautions in the capturing photo phase (distance from smartphone to the plate, lightness, type of resolution of the device used): not optimal condition to exposure can determine biased estimate of the calories and the nutrient components. It is evident these systems can be efficient if an accurate digitalization measurement process can be applied. This paper proposes an approach for evaluating the quality data in digitalization process through identification and testing of the minimum condition request for the correct functioning of these systems. The analysis has been implemented on photos of ice-cream under several measurement conditions. The conversion in bitmap and after in image matrices. These matrices can be evaluated in a heatmap approach. The ideal plate, that satisfies the measurement aspects, comes from the application of severe rules of clustering methods (Zhao, 2014).
6 6 Web misinformation: A text-mining approach for legal accepted facts SANTARCANGELO V.*, BUONDONNO A.**, ODDO G.**, STAFFIERI F.P.***, SANTARCANGELO N.****, MARAGNO M.*****, TRENTINELLA F.****** *Centro Studi S.r.l., **iinformatica Srls, ***Studio Legale Staffieri, ****BNG SpA *****Ordine degli Ingegneri della Provincia di Matera, ******Università Telematica E-campus More and more information appear in the web every day, in our world interconnected by the web. However, the growing of misinformation (unintentional inaccurate information) and disinformation (intentional inaccurate information) of the web contents introduces a lot of noise in the analysis and results of Big Data. In this work we show a review about the information web spoofing and introduce an innovative system as solution about the investigation of the notoriety of web data. Our system is based on a web crawler that performs a text mining activity on web data about an input text data considered by the user. The system considers the recurrence of the web data (input), weighing every entries found thanks to a knowledge base that associates a notoriety weight (from -3.0 for worst notoriety to +3.0 for best notoriety) to the website (e.g. the website has notoriety +3.0, the website has notoriety +2.0, the website nonciclopedia.wikia.com has notoriety -3.0). The knowledge base, developed by us, considers over 1000 websites and it can be shared and improved for research tasks. Our tool permits to provide a prototypal filtering system for the misinformation that is a Big data problem for the web contents. It can be useful for search engines and also as tool for web browsers (it is able to suggest the notoriety of a displayed web content). As case study, in this paper, we consider the usability of a web data content as accepted fact in legal context, that represents an actual open topic. The importance of this topic can be related to the no update of the regulations and from the growing of fake information on the web. In this work we show the legal context about accepted fact in Italian legislation and propose our filtering system as possible tool for legal field that aims to provide a statistical estimate about the legal acceptance of a web data. In fact, the results obtained by the system permit to return a weighted score about the notoriety of the data that become an useful feedback to consider the web-data as an accepted fact in legal context.
7 7 Factorial analysis of end-to-end performance evaluation of Italian higher education institutions TOMA E.*, D UGGENTO A.M.*, RICCI V. ** *Department of Economics and Mathematics, University Aldo Moro of Bari; **Statistics, Research and Programming Services, University Aldo Moro of Bari We carry out an end-to-end bibliometric performance analysis of Italian higher education institutions (HEIs) using data from the latest (2014) release of the Scimago Institutions Rankings (SIR). We track six variables through the following chain: inputoutput-excellence-outcome-productivity. Factorial analysis (FA) then allows us to ascertain that the primary indicators are orthogonal and represent a quantity and a quality/productivity dimension respectively. Productivity of research is computed either in term of output or outcome. The quantity dimension is size-dependent while the quality and productivity dimension is sizeindependent. We also carry out an analysis of performance according to the geographical area where Italian HEIs are located.
8 8 Sensory evaluation of seven white wines to define consumers preference by key intrinsic attributes to wine choice PISCITELLI A.*, D AMBROSIO A.** *Department of Political Science, University Federico II of Naples; **Department of Industrial Engineering, University Federico II of Naples; The complexity of the wine market has constrained researchers to try different methods to define how consumers choose wines. Price, brand, region of origin, grapes and gained awards are the key extrinsic attributes used by different consumer groups when choosing wine. This paper addresses the problem of measuring the key intrinsic attributes that characterise the wine, based on specific sensory categories and the impact on consumers in terms of preferences. To this end it has been conducted a sensory evaluation experiment on seven white wines by 11 judges; for each wine, the judges had to express a preferential judgment by stating a value in a ten-point scale in which one means the worst, ten means the best. The experiment was conducted by following a double-blind control procedure. We analysed the wine attributes with a multidimensional unfolding methodology using PREFSCAL algorithm (Busing et al., 2005). The sensory evaluation of wines is used in order to define a procedure to draw a profile of consumers, their discriminatory capability and to understand how the key intrinsic attributes influence the consumer s preferences. Keywords: Sensory analysis, Unfolding, Consumer s preferences, Key intrinsic attributes.
9 9 Issues in designing an index of trust for public institutions BOLZAN M.*, MAROZZI M.** *University of Padua, **University of Calabria A large and growing body of research shows the low and declining trust in public institutions, in particular in political parties and representatives. Governments are very concerned about this downtrend in trust because it can lead to falling democratic participation and falling engagement in civic activities, tax evasion and decline in lawabiding behavior, which in turn can lead to problems of governmental legitimacy and even threaten the survive of a democracy. Mistrust decreases social capital which has an important role in promoting economic development, wellbeing and safety, in reducing poverty and crime. Recently, and in particular from the 2008 financial crisis, public institutions have faced reduced funding as well as even stricter requirements for transparency and efficiency. Reforms have been introduced, like ethics regulation to ensure that public officers display trustworthy standards of conduct. Many government administrations launched projects to measure their citizens' trust with public institutions. Customer satisfaction with specific public services or trust with specific public institutions have been studied widely, but less attention has been paid to measure citizens' general trust in public institutions. Unfortunately, it is quite difficult to measure trust because of its elusive meaning. The problem of measuring the general level of trust in public institutions is addressed using composite indicators. In particular, the most important design issues in designing an index of trust in public institutions are discussed, among them: how to summarize, standardize, weight and pool together the data. Uncertainty analysis is shown to be very useful in assessing the robustness of the index. A practical application to data from the last round of the European Social Survey is presented. The data refer to the trust in seven public institutions: country's parliament, legal system, police, politicians, political parties, European parliament, United Nations. 29 European countries are considered. The results show that Scandinavian countries are the most trustful countries whereas former communist countries are generally ranked among the least trustful ones. The Iberian and/or Mediterranean countries of Cyprus, Spain and Portugal are the only non former communist countries ranked among the least trustful ones.
10 10 Business enterprises and economic system: subjective expectations MARIANI P., ZAVANELLA B. Department of Economics, Management and Statistics, Bicocca University of Milan Forecasts are a major problem for planning activities in the firm framework. The statistical and econometric models used for this purpose require knowledge of official data, which are communicated with a certain time lag. Models formulation and application also require time. From all this it follows that models forecasts are made available with a sure delay. Furthermore, statistical models are founded on the historical realization of the analyzed variable; if a sudden change occurs in the structure of the variable, this break can take some time to be captured by the models. An important source of information that could help to answer these questions are surveys on subjective qualitative expectation addressed to firms. Actually, entrepreneurs are often able to pick up some signals from the economic system, on the contrary, statistical models cannot perceive unforeseen event in advance. There are a lot of qualitative survey, one of these is carried out by Federmeccanica and investigate the sentiment of the producer of metallurgic sector of Italian industry. Among the questions contained in this survey two are of particular interest: the production in the last quarter is increased, decreased or is unchanged? ; what is the expectation for the next quarter? In this application the analysis is conducted as follows. At a first step, balances of forecast are compared with the final data of the same quarter, to establish coherence between the two answers. Then the balances series is graphically compared with official data of industrial production index numbers. Finally are constructed simple univariate models for short term forecasts and the obtained results are compared with the ones supplied by Federmeccanica, to test the forecast capabilities of this survey as already discussed. This procedure is of particular interest because in the last years an unforeseen great crisis occurred and subjective expectation can be very useful in these cases. The original contribution is the use of subjective expectations in a model based on Istat data. Keywords: Measurement of expectations; strategic decisions
11 11 Process mining: Review and a case study D ALESSANDRO M.T*, GAUDIANO G.*, COLUCCI M.*, SANTARCANGELO V.***, ROMANO A****, MINERVA T.***** *Sudelettra S.p.A., **L Antincendio S.r.l., ***Centro Studi S.r.l., ****iinformatica S.r.l.s. *****Università degli Studi di Modena e Reggio Emilia The process mining is defined as a research to discover, monitor and improve real process (i.e., not assumed processes) by extracting knowledge from event logs readily available in today s system [P. van der Aalst]. Discovering a process models by event logs and by actual process monitoring can be seen as a research field belonging to Big Data Analysis oriented to process development. In fact, process mining aims to design a Process Model (Discovery Mining), by identifying the differences between a real process and a model (Conformance Checking), to extend and improve the devised process model (Enhancement). This work shows the state of the art of Process Mining considering the potentiality of data retrieval on Enterprise Resource Planning (ERP) Systems (e.g. Microsoft Dynamics NAV) as well as how the Process Mining performances can be enhanced by using Semantic Networks. In a case study on ERP Systems, we show an application of Process Mining related to a Maintenance Extinguishers process. The considered process involves different entities: customers, maintainers, administrative employees, fleet and park of devices for fire protection. The interactions among these entities determine the process dynamics, that can be identified by process mining analysis of the ERP systems. Due to the analysis of logs and records (e.g. worktops, invoices) on business management systems, it has been possible analyzing the process of maintainers and define a theoretical model describing the real process of Maintenance Extinguishers (Discovery Mining). The parallel analysis of some questionnaires compiled by maintainers about their tasks and the fieldwork analysis of their activities have permitted the real process representation. The comparison between the process model and the real process (Conformance Checking) have allowed identifying some process discrepancies, inconsistencies and inefficiencies and defining some improvement actions, aimed at quality development of the business process
12 12 A fractional design to elicit graduates' preferences for job characteristics FABBRIS L., SCIONI M. Statistics Department, University of Padua A relevant feature of the surveys held through electronic questionnaires is the widespread use of statistical experiments, that are typically embedded into survey designs. There are experiments, called 'fractional', in which the alternatives obtainable combining the response options of all the experimental variables are so numerous that it is necessary to sample and administrate them in a random fashion in order to reach the knowledge targets. We applied a fractional experiment to a survey to collect data about the criteria that early graduates adopt as guidance for choosing a job among the offered ones. The survey was conducted by interviewing, with a self-administered questionnaire, a sample of students of Padua University who graduated in The data collection was assisted by a CAWI (Computer Assisted Web -based Interviewing) system. The questionnaire was designed to highlight the mental process of early graduates when they are offered a job in scenarios that portray the current Venetian local markets. The experimental procedure consisted of a set of questions to describe graduates choice mechanism based on the simulation of their choice of the job which, among those offered, best fitted their expectations. Jobs were characterised by a set of interrelated ( conjoint ) features (e.g. work contract duration, career perspectives, distance from home, flexibility of work time, level of autonomy). The experimental attributes were as follows: (a) width of the choice set (varyi ng between 2 and 6) administered to graduates, (b) number of variables that described the job offer (this number was inversely proportional to the choice set width so that the product between the two numbers be always 12), and (c) the way graduates identified the preferred attributes of the chosen job offer. Any job characteristic was defined by two possible alternatives. A number of 3,600 questionnaires was collected. The paper presents the experimental design and the basic indicators for measuring the effectiveness of the design.
13 13 An experiment to define the optimum salary for fresh graduates FABBRIS L., RAPISARDA L., SCIONI M. Statistics Department, University of Padua The economic downturn has had a significant effect on the composition and characteristics of the labour market. So, even though employment conditions of graduates are better than those of secondary school leaving certificate holders, the labour market has become difficult even for graduates. Fewer jobs are available and low-paying contracts or internships are often offered to fresh graduates at their first work experience. The salary, although it is not the only thing that concerns graduates, and sometimes not even the most important, is a relevant aspect when they evaluate whether to refuse or accept a job. What kinds of salaries do graduates expect to earn upon graduation? The salary expectations of students match the reality of the job market and the willingness to pay by entrepreneurs? To answer these questions, we applied a completely randomized design with a single factorial experiment. Graduates were not asked directly the minimum salary they would accept upon graduation, but their willingness to accept a job was elicited experimenting the admissibility of 4 different salary levels: 600, 800, 1000 and 1200 euros. Moreover, in order to define the value system of graduates, we investigated the importance attached to a set of perks singly posing questions about the tradeoffs between giving up 100 salary and getting other benefits. The data come from a survey conducted by interviewing, with a self-administered questionnaire, a sample of students of Padua University who graduated in The data were collected through a CAWI (Computer As sisted Web-based Interviewing) system. A number of 3,600 questionnaires was collected. This paper presents the main results of the analysis of data processed through multivariate analyses. We highlighted the differences in the graduates willingness to accept a job, according to the level of the achieved degree, the subject of the study programme, the final mark and other social and curricular variables.
14 14 Misurare il comportamento istintivo durante la fruizione di messaggi pubblicitari, logo aziendale e navigazione internet con la rilevazione dell attività cerebrale, emozionale e di puntamento dello sguardo: il caso di Telecom Italia/TIM. MANDARANO A., TRETTEL A. Telecom Italia, BrainSigns Il principale tema di ordine metodologico che l intervento intende affrontare riguarda la necessità e la possibilità concreta di poter misurare l emozione nelle persone durante la fruizione di messaggi pubblicitari. E infatti noto dalle neuroscienze come i sistemi cerebrali collegati all emozione giochino un ruolo fondamentale, e spesso sottratto al controllo cognitivo cosciente, durante le decisioni che generiamo ogni giorno. Si propone una presentazione delle applicazioni in TelecomItalia/TIM di tecniche di neuromarketing per misurare la reazione istintiva di emozione e di interesse dei consumatori durante la fruizione di materiali di comunicazione pubblicitaria. Infatti, il settore di ricerca sulla comunicazione di TelecomItalia/TIM ha attivato nel corso degli ultimi cinque anni una collaborazione stabile con l Università Sapienza di Roma per la messa a punto di un sistema scientificamente appropriato di rilevazioni dell impatto cerebrale e emozionale della propria comunicazione pubblicitaria sui vari canali di diffusione disponibili. Verrà illustrato come si possano misurare con tecnologie avanzate e rigore scientifico l impatto emozionale e di interesse generato dalla i) comunicazione pubblicitaria relativamente a spot e annunci stampa, ii) percezione di logo in studi di re-branding e iii) ottimizzazione della navigazione sul sito web. Si tratterà di come l emozione sia necessaria alla formazione di memoria di brand e di come sia un driver fondamentale di scelta o di acquisto con meccanismi che sono poi alla base di molta parte del nostro decision-making quotidiano. Verrà mostrato come le informazioni acquisibili mediante la rilevazione neurometrica consentano di indagare su una sfera importante dei comportamenti di preferenza e scelta dei consumatori che completano ed integrano quelle ottenibili con dichiarazioni esplicite verbali in interviste o focus group. Molto spesso le emozioni percepite durante le stimolazioni sensoriali a cui siamo sottoposti nella vita di tutti i giorni non si appalesano al nostro controllo cosciente, pur guidando invece il nostro comportamento percepito come spontaneo o naturale. Spesso infatti non siamo in grado di giustificare razionalmente i nostri comportamenti di acquisto, che sovente differiscono di molto dal nostro intento iniziale a favore di un acquisto deciso sul momento in base a motivazioni puramente istintive. La novità tecnologica e metodologica di questo intervento è che tali emozioni (ed i relativi processi cerebrali che le accompagnano) possono essere misurati durante la fruizione di messaggi pubblicitari in condizioni sempre più ecologiche, vicine cioè a quello che accade nella vita di tutti i giorni. Questo è possibile grazie ad avanzamenti metodologici e tecnologici dei dispositivi di misura dell attività cerebrale ed emozionale dell uomo che oggi possono tranquillamente essere impiegati al di fuori dei laboratori scientifici delle università o dei centri di ricerca.
15 15 Saranno per questo riferiti esempi concreti dell esperienza diretta di TelecomItalia/TIM negli ultimi anni in cui questi metodi di ricerca neurometrica sono stati inclusi positivamente nel processo di brand research, a integrazione dei metodi più tradizionali, con strumenti atti ad essere impiegati anche fuori dai laboratori universitari. Saranno presentate evidenze concrete di come i comportamenti di preferenza e scelta dei consumatori indagati con tali tecniche innovative abbiano prodotto suggerimenti utili in azienda per il miglioramento/ottimizzazione della comunicazione, nelle modalità di presentazione dei servizi offerti e nella fruibilità di contenuti digitali e non, con riferimento anche agli orientamenti di target user e non user.
16 16 Analysis and implementation of a NPS (Net Promoter Score) Survey: The Ariston Thermo case DEGAN L.*, GUIDETTI C.**, MORICHI M.** *Galgano & Associati Consulting, **Ariston Thermo SpA Ariston Thermo Group decided that Customers must be their Best Promoters, so to monitor Customer Satisfaction and Loyalty trend by a periodic NPS (Net Promoter Score) Survey, focused on evaluation of Service, in the different market areas. The origin of this study lies in the presence not always clear and coherent of documentation currently available concerning the statistical bases, which NPS index is based on. NPS is a management tool that can be used to gauge the loyalty of a firm's customer relationships, as an alternative to traditional customer satisfaction research and claims to be correlated with revenue growth. The NPS, is based on the fundamental perspective that every company s customers can be divided into three categories: Promoters, Passives, and Detractors. By asking one simple question How likely are you to recommend ARISTON THERMO GROUP to your friends/colleagues? you can track these groups and get a clear measure of your company s performance through your customers eyes. NPS is calculated by subtracting the percentage of customers who are Detractors (score 0-6) from the percentage of customers who are Promoters (score 9-10): the Promoters are considered generators of positive contacts, Detractors negative contacts, whereas Passives (7-8) are considered not having any influence on promoting the Firm s Products &Services. To model the NPS, promoters are labeled +1, passives 0, detractors 1, in the given proportions p 1 of promoters, p 0 of passives, and p 1 of detractors, with p 1 +p 0 +p 1 =1. NPS Index corresponds to the mean of x-scores distribution. If everyone is a Promoter, the Net Promoter Score is 1 (or 100%); if everyone is a Detractor, it is -1 (or - 100%). The study characterizes the statistical model of NPS, in order to design a NPS survey statistically significant and representative and applies appropriate estimation and testing criteria to periodic Ariston Thermo NPS Survey. In particular, for understanding the statistical proprieties of NPS index, the variance of x-scores distribution is studied: how it varies with respect to NPS values and the proportions of Detractors and Promoters. The study provides some suggestions concerning suitable sample sizing (at least 450 responses per quarter), based on proportions estimated by a recent pilot Survey, and shows result of pilot test. During 2015 Ariston Thermo Group NPS project shall be implemented in Italy, Germany, China, Turkey, Russia, UK and Spain. In total the project will involve about 20,000 respondents/year. Questionnaires will be submitted by phone interviews (CATI). For detractors, an internal manager closes the loop by recalling them and whenever possible help them to solve their issues with the aim of improving their satisfaction level. First results in Italy for 1st Quarter 2015 are 49% for Product NPS and 54% for Service NPS. While the former is stable, the latter shows a higher variability among months. As
17 17 detractor level is stable, results from service NPS questionnaire will supply information about how to move consumers from passives to neutral cluster.
18 18 Embedding covariates in conjoint analysis models GIORDANO G.*, LAURO C.N.**, SCEPI G.** *Dept. of Economics and Statistics, University of Salerno; ** Dept. of Economics and Statistics, University Federico II of Naples ; The aim of this paper is to define an integrate scheme of analysis where different kinds of information are retrieved in suitable data matrices according to: i) the role of the variables (active/illustrative; response/predictor), ii) the kind of data (quantitative/ qualitative) and iii) the purpose of the analysis (exploratory/confirmatory). We start from the formulation of the traditional Multivariate Linear Regression model that considers a set of multiple responses linearly related to a set of predictors. According to the quantitative or categorical nature of data, different specification of the model can be derived (e.g. MANOVA, MANCOVA, Seemingly Unrelated Regression, see Timm, 2002). The interest in this formulation arises from the specification of the metric approach to Conjoint Analysis, (Green and Srinivasan, 1990), which is one of the most famous techniques to analyze preference models at individual level. The data structure of the Conjoint Model is fully consistent with a multiple regression analysis with multiple preference responses revealed by a set of judges. In this paper it is proposed a unified approach to investigate the typical data structure of Conjoint Analysis models in the framework of Exploratory Data Analysis. Firstly, the Factorial Approach to Conjoint Analysis is recalled, (Lauro et Al., 1998) and then, we introduce an L-shaped data structure where several variables are available as external information (socio-economic variables observed on the judges). By taking into account the kind and the role of information retrieved in each data matrix (either metric or dummy variables), we aim at showing how to mine preference data from this peculiar data structure. We derive a unique formulation to investigate both the relationships among the different sets of predictors. Namely, we express the preference response variables as a function of two sets of predictors: inner and outer arrays in the language of Design of Experiments (Giordano and Scepi, 1999). In the analysis of preference models, this allows to take into account the effects of the stimulus attributes and the Judges characteristics on the elicited preference. Finally, an inter-relationships coefficient matrix will be derived. The geometric interpretation of these methods can help to understand their common traits and allows the graphical displays and the interpretation of the different models. Indeed, the powerful graphical tools of exploratory methods have proved to be valuable in many applicative fields (Giordano and Scepi, 2012; Giordano et Al., 2011; Lauro et Al., 2008). References Giordano G., Scepi G. (2012). Network Data as Contiguity Constraints in Modeling Preference Data. In: AA.VV. Challenges at the Interfaces of Data Analysis, Computer Science and Optimization. Springer, Berlin Heidelberg: pp Giordano G., Scepi G. (1999), Different informative structures for q uality design, Journal of the Italian Statistical Society, 8, 2-3, pp Giordano G., Lauro C.N., Scepi G. (2011). Factorial Conjoint Analysis Based Methodologies. In: AA.VV.. Classification and Multivariate Analysis for Complex Data Structures. Springer, Berlin Heidelberg: pp.17-28, Vol. XIX. Green P. E., Srinivasan V. (1990), Conjoint Analysis in Marketing: New Developments with Implications for Research and Practice, The Journal of Marketing, Vol. 54, 4, pp
19 19 Lauro C.N, Scepi G., Giordano G. (2008). Conjoint Analysis based methodologies for the ex-ante evaluation of regulatory impact. SA-IJAS, Vol. 3-4, pp Lauro C.N., Giordano G., Verde R. (1998), A Multidimensional Approach to Conjoint Analysis, Applied Stochastic Model and Data Analysis, 14, Wiley, pp Timm N. H. (2002) Applied Multivariate Analysis, Springer, New York.
20 20 PLS path modelling for the evaluation of patients' satisfaction of a department GALASSO R.*, GRASSIA F.**, GRASSIA M.G.*, ZAVARRONE E.*** * Dept. of Social Science, University of Naples Federico II; ** General directorate, ISTAT; ***Dept. of Marketing, Communication and Consumer Behavior, IULM University of Milan Patient satisfaction surveys are gaining in importance and should be at the heart of any healthcare facility. It's valuable to get a holistic view of what patients really think about the care and treatment they receive. Patient satisfaction can be measured by methods based on latent variables, i.e., variables that are not directly observed but deducted from mathematical analysis. Those methods include the partial least squares (PLS) path modelling aimed at defining optimal linear relations among latent variables in order to assemble the best set of predictions. Aim of this paper is show an application of patient satisfaction survey made on the Department of Day Surgery of the Caserta' Hospital. One hundred patients of this Department ware interviewed from April and to May 2011, a month after their surgery, with a CATI technique. The Questionnaire, consisting of 36 items has investigated on seven categories of performance: quality of the facilities, quality and clarity of provided Information, quality of relationship with surgeons and nurses, quality of the received care, quality of life, overall patient satisfaction. We decided to consider the quality of life after the surgery as latent variable that affects satisfaction. The use of this latent variable was an innovation for a patient satisfaction model. For the analysis of data, collected through the questionnaire, was used the PLS path modelling. The model was constructed by correlating three exogenous latent variables (Facilities, Information and Service, Relationship), with the latent endogenous variable Perceived Quality. This variable and the variable Quality of Life were correlated to the endogenous variable Satisfaction. At the end, the variable Satisfaction was correlated to the endogenous latent variable Loyalty. The results were very interesting: overall Perceived Quality was the variable with greatest (54%) positive impact on patient satisfaction, but Quality of Life had a good impact to (36%). As previo usly mentioned, the use of this latent variable is an innovation, and therefore his good impact means a good result. For the manifest variables, professionalism of surgeons and nurses positively affected the level of satisfaction, conversely waiting times, quality of post surgery care adversely affected the level of satisfaction. In conclusion, PLS path modelling may represent a valuable tool to measure quality in the setting of managed health care since it allows for the identification of areas where the service can be improved. References: Grogan S., Conner M., Willits D., Norman P. Development of a questionnaire to