Validation and psychometric properties of a short version of Young's Internet Addiction Test

The phenomenon of excessive or pathological Internet use has been investigated in the last decades in order to reveal psychological correlates as well as potential treatments. A key element of the respective research and clinical practice is a valid and reliable diagnosis of pathological Internet use. One of the most frequently used questionnaires is Young's Internet Addiction Test (IAT). However, the factorial structure of the IAT is still discussed controversially. In four studies with different samples we a) addressed the factorial structure of a German version of the IAT with exploratory factor analysis and reduced the items to those with sufficient factor loadings and item characteristics, b) checked the factorial structure using confirmatory factor analysis, and c) analyzed convergent, divergent and incremental validities. We revealed a short version of the IAT, which consists of 12 items and a two factorial solution and good reliability (study 1). The two factors were named " loss of control/time management " and " craving/social problems ". This two factorial solution was confirmed by the confirmatory factor analysis (study 2) and we have found good indices for convergent, divergent and incremental validity (studies 3 and 4). In conclusion, the short version of the IAT has good psychometric properties and represents the Internet addiction's key elements based on the proposed diagnostic criteria. We suggest that with the 12 item version of the IAT, future studies can more reliably assess the problems individuals experience in their daily life due to an excessive usage of the Internet or specific applications, respectively.