Efficacy

Efficacy refers to the ability to perform satisfactorily. In psychology, self-efficacy (by Albert Bandura) refers to people’s beliefs in their innate abilities to actualize their goals. For instance, a student with a high self-efficacy will tend to manifest hard work due to his confidence that he can achieve success while someone with low self-efficacy will tend not to bother exerting useless effort. In pharmacology, this refers to the capacity of a drug or intervention to cause improvement as compared to a placebo or another treatment.