Patricia Benner introduced her theory of novice to expert in 1984 to conceptualize how nursing expertise develops progressively through 5 stages as nurses gain knowledge and experience. These stages are novice, advanced beginner, competent, proficient, and expert. Benner expanded on this research in a later work, examining skill acquisition, critical thinking, and ethical behavior in nursing practice. The theory aims to determine the nature of clinical knowledge in nursing and how nurses can achieve expert status.