Human factor

A human factor (hereinafter, the Factor) is an individual's characteristic such as appearance, attitude, capacity, habit, and motivation that contributes to this individual's interaction with his or her surrounding cultures, systems, environments, and other human beings, and, consequently, impacts his or her performance.

Human factors (alternatively known as ergonomics) is the scientific discipline of studying interactions between humans and external systems, including human-computer interaction (HCI). When applied to design, the study of human factors seeks to optimize both human well-being and system performance.