Risk and resilience factors presumably explain the individual differences in the response to adversity. However, little is known about how such factors are related. Risk and protective factors may reflect a quantitative difference along a single dimension (e.g., low IQ might be associated with risk and high IQ with resilience); however, they may also refer to orthogonal constructs that interact and/or moderate stress effects to increase or diminish the probability of developing trauma-related psychopathology (e.g., good coping could offset low IQ). The authors illustrate experimental strategies for distinguishing between these possibilities for any putative measure relating to symptom development, using a database that includes published and unpublished psychological and biological variables from a relatively homogenous cohort of exposed and nonexposed veterans.