This document discusses risk assessment and its effectiveness in informing safety-related decisions. It provides definitions of risk from academic literature and standards documents. Risk is defined as the "effect of uncertainty on objectives" which takes into account uncertainty in consequences and likelihood. Risk assessment is then defined according to various standards organizations, though their definitions vary. The document outlines the risk management process from ISO 31000 and compares various risk management frameworks. It then discusses what makes an effective risk assessment, including planning, communication, and continuous monitoring and review. Lastly, it summarizes the results of a survey on risk assessment processes and techniques used.