Evaluation of the psychometric properties of the Italian Internet Addiction Test.

Since the diffusion of Internet addiction has emerged in several cultural contexts, it seems relevant to study the properties of the Internet Addiction Test (IAT)-the most widely used screening instrument-across various cultures. In Italy, only one study has examined the IAT factor validity, and a comprehensive investigation of its psychometric characteristics is so far lacking. The purpose of this study was to perform a psychometric analysis of the Italian IAT. A total of 840 students (Mage=18.65 years, SD=3.85 years; 59% female) were recruited. Pertaining to scale dimensionality, the best-fit measurement model includes two factors: "Emotional and cognitive preoccupations with the Internet and social consequences" and "Loss of control and interference with daily duties" (χ(2)/df=3.38; comparative fit index=0.88; Tucker-Lewis Index=0.87; root mean square error of approximation=0.07), which together explained 45.59% of the variance. Internal consistency Cronbach's alpha values ranged from 0.83 to 0.86. Convergent validity was demonstrated, with significant correlations between IAT and Generalized Problematic Internet Use Scale 2 scores. The Italian version of the IAT was found to have good psychometric properties and a two-factorial structure. Identification of the IAT dimensions may help to define the construct better and develop intervention strategies.