GNGTS 2015 - Atti del 34° Convegno Nazionale

There are twomain approaches in studying risk perception, the realistic and the constructivist. The realistic approach considers the perception of risk very close to the probability that an actual event occurs; in this meaning, it would be sufficient to have more information in order to have a better perception of risk. The constructivist approach thinks the risk is not “objective”, but subjective and socially constructed. To understand risk perception it is necessary to consider a number of social, psychological and cultural ambits, as well as interaction among them (Wachinger and Renn, 2010). In our opinion, in agreement with the constructivist approach, seismic risk perception does not depend on the actual value of the seismic risk but there are others factors influencing it. In the specific case of seismic risk, the role of people perception is very important, especially in the absence of clear communication strategies. The clarity of the language used by mass media, scientists and decision-makers in communicating seismic risk to people is essential for a proper knowledge and awareness. Amore thorough discussion of these aspects can be found in our recent publications (Crescimbene et al., 2015; Crescimbene and La Longa, 2015). The surveys on the seismic risk perception in Italy. Within the DPC-INGV project S2 2012 and 2014 - Constrain Observation into seismic hazard - a research activity was funded to assess seismic risk perception in Italy. In the first year (2012-2013) a questionnaire was built to assess seismic risk perception, with a particular attention to compare hazard perception with the hazard as defined by science and by law (namely hazard “by law”). The questionnaire was managed by web (www.terremototest.it ). Until July 31, 2014 over 8,500 answers were collected (Crescimbene et al., 2014). In the second research period (2014-2015), we implemented the questionnaire with a session dedicated to collect information on the seismic vulnerability of the houses of the interviewees. Furthermore, to achieve a statistically significant sample at national level, we conducted a CATI survey (Computer Assisted Telephone Interview) on over 35,000 people to obtain a statistical sample of 4,012 people. The present paper presents the principal findings of both, web and CATI survey. Methodology. The Seismic Risk Perception Questionnaire (SRP-Q) is designed by semantic differential method (Osgood, 1957), using opposite terms on a Likert scale to seven points (Likert, 1932). The questionnaire allows the scores of five risk indicators to be obtained: Hazard, Exposure, Vulnerability, People and Community, Earthquake Phenomenon. The values 1 to 4 indicate low scores of perception, on the contrary, values greater than 4 up to 7 (the maximum value of the scale) indicate higher scores of perception. In the past S2-2012 DPC-INGV Project, the questionnaire on the perception of seismic risk was built and tested. Up to July 2014, over 8,500 questionnaires were collected via web (the questionnaire can be filled at: http://terremototest.it .). Statistical analysis carried out on this data set showed a good reliability of the items that compose the indicators of Hazard, Exposure and Vulnerability. Indeed, the assessment of the Cronbach alpha values (Cronbach, 1951) showed good values for the Hazard ( =0.86) and Vulnerability ( =0.94) indicators. On the contrary, Exposure indicator had an insufficient Cronbach alpha value ( =0.52). It was necessary to execute a factorial analysis named Principal Component Analysis (Bolasco, 1999) in order to identify two latent variables, that may be reduced to “tangible” or “intangible” elements of the territory considered. The items of Exposure indicators were grouped in these two variables, and a new computing of Cronbach alpha was executed, obtaining values greater than 0.70. The review of the questionnaire was made after the meeting held in September 2014 at the DPC. During the meeting the questionnaire was distributed and discussed. After the meeting there have been some slight modifications to the questionnaire. The main change concerned question 4. The former question “In case of an earthquake, how would you describe the institutions and the people around?”, was changed in “In case of an earthquake, how would you describe the community and the people around?”. With respect to the previous version, minor changes were made on the closed-ended questions and on the comparison between earthquake and other natural risk. GNGTS 2015 S essione 2.3 293