The following is a summary of the author’s fivestage model of adult skill acquisition, developed in collaboration with Hubert L. Dreyfus. An earlier version of this article appeared in chapter 1 of Mind Over Machine: The Power of Human Intuition and Expertise in the Era of the Computer (1986, Free Press, New York).

Stage 1: Novice

Stage 2: Advanced Beginner

Stage 3: Competence

Stage 4: Proficiency

Stage 5: Expertise