 In the risk sciences, it is common to distinguish between “objective risk” and “subjective risk”. The former concept is in principle fairly unproblematic since it refers to a frequentist interpretation of probability. The latter concept is more ambiguous. In the psychometric literature on risk from the 1970s, subjective risk was often conceived as a subjective estimate of objective risk. In more recent literature, a more complex picture has emerged. Subjective appraisals of (the severity of) risk depend to a large extent on factors that are not covered in traditional measures of objective risk, such as control and tampering with nature. If the terms are taken in this sense, subjective risk is influenced by the subjective estimate of objective risk, but cannot be identified with it. In the psychological literature, subjective risk is often conceived as the individual’s overall assessment of the seriousness of a danger or alleged danger. Such individual assessments are commonly called “risk perception”, but strictly speaking the term is misleading. This is not a matter of perception, but rather a matter of attitudes and expectations. Subjective risk can be studied with methods of attitude measurement and psychological scaling (Sjöberg 2004).