A global scale comparison of risk aggregation in AI assessment frameworks

AI applications bear inherent risks in various risk dimensions, such as insufficient reliability, robustness, fairness or data protection. It is well-known that trade-offs between these dimensions can arise, for example, a highly accurate AI application may reflect unfairness and bias of the real-world data, or may provide hard-to-explain outcomes because of its internal complexity. AI risk assessment frameworks aim to provide systematic approaches to risk assessment in various dimensions. The overall trustworthiness assessment is then generated by some form of risk aggregation among the risk dimensions. This paper provides a systematic overview on risk aggregation schemes used in existing AI risk assessment frameworks, focusing on the question how potential trade-offs among the risk dimensions are incorporated. To this end, we examine how the general risk notion, the application context, the extent of risk quantification, and specific instructions for evaluation may influence overall risk aggregation. We discuss our findings in the current frameworks in terms of whether they provide meaningful and practicable guidance. Lastly, we derive recommendations for the further operationalization of risk aggregation both from horizontal and vertical perspectives.