In this chapter, we report on three psychometric scaling studies, summarized in Table 1. In each study, participants rated a given set of hazards on a range of risk characteristics and indicated the degree of risk reduction and regulation they desired. Based on this data, we explore the relationships among risk characteristics and a smaller number of dimensions (factors) derived from them. We also relate risk characteristics to people's perception of risk and their desire for risk reduction and regulation. Our work builds on and extends earlier studies with a smaller number of hazards and risk characteristics (Fischhoff et al., 1978).