The Development and Validation of the (C-ISO) Scale.

Tools designed to measure the cognitions of individuals who engage in sexual activities with children over the Internet are either based on knowledge about men who had committed contact sexual offenses or cognitive phenomena not specifically associated to offending behaviors. Thus, there is no validated tool specifically designed to assess the offense-supportive cognitions of men who use the Internet to sexually offend children. This study developed and validated the (C-ISO) scale. A sample of 241 men with online and contact sexual as well as with nonsexual offenses completed the C-ISO scale and its psychometric properties, and latent structure was analyzed using both Classical Test Theory (CTT) and Item Response Theory (IRT), resulting in a final version containing 31 items. The analyses indicate that the C-ISO has excellent psychometric properties and discriminates men with online sexual offenses from those with contact sexual and nonsexual offenses. Implications of the findings for clinical practice and future research are discussed.