The development of the Survey of Knowledge of Internet Risk and Internet Behavior is described. A total of 1,366 Grades 7 and 8 male and female students from an urban, suburban, and rural school offered agree-disagree responses to 26 statements defining one Knowledge Scale and five behavior dimensions. Literature-based support is presented for content validity. Construct validity support for the hypothesized dimensions is provided through Rasch model analysis of the Knowledge Scale supporting a unidimensional, hierarchically ordered scale. Latent class analyses provided support for the utility of the five categorical behavioral dimensions. Implications for instrument developers and educators are discussed. (Contains 1 figure and 4 tables.)