There exists a number of multidimensional measurement scales for problematic Internet use (PIU) with varying factor structures. This study reviews the factor analytic techniques used to develop these measures and discusses their implications for the factorial validity, particularly discriminant validity, of these PIU scales. To further illustrate these points, we reformulate the four-factor Online Cognition Scale into a more parsimonious two-factor measure (i.e., dependency and distraction) and demonstrate its factorial validity as well as robustness across student and working adult samples. Contributions of this research are discussed.