This paper explores the concept of effective human oversight in high-risk AI applications, drawing insights from psychology, law, philosophy, and technical domains. The authors propose that effective human oversight is characterized by four key conditions: causal power, epistemic access, self-control, and fitting intentions. They argue that these conditions are equivalent to moral responsibility and fitting intentions. The paper discusses facilitators and inhibitors of effectiveness in human oversight, categorized into technical design features, individual factors of oversight persons, and environmental circumstances. Additionally, the paper analyzes the European AI Act, particularly Article 14 on Human Oversight, to evaluate its alignment with the proposed conceptualization of effective human oversight. The analysis highlights both the strengths and weaknesses of the AI Act, suggesting that it provides a more general and practically useful framework for understanding effective human oversight.This paper explores the concept of effective human oversight in high-risk AI applications, drawing insights from psychology, law, philosophy, and technical domains. The authors propose that effective human oversight is characterized by four key conditions: causal power, epistemic access, self-control, and fitting intentions. They argue that these conditions are equivalent to moral responsibility and fitting intentions. The paper discusses facilitators and inhibitors of effectiveness in human oversight, categorized into technical design features, individual factors of oversight persons, and environmental circumstances. Additionally, the paper analyzes the European AI Act, particularly Article 14 on Human Oversight, to evaluate its alignment with the proposed conceptualization of effective human oversight. The analysis highlights both the strengths and weaknesses of the AI Act, suggesting that it provides a more general and practically useful framework for understanding effective human oversight.