19.1 INTRODUCTION
Many aspects of intelligent tutoring systems (ITS) are addressed in a search for answers to the following main questions: (a) What are the precursors of ITS? (b) What does the term mean? (c) What are some important milestones and issues across the 20+ years of ITS history? (d) What is the status of ITS evaluations? (e) What is the future of ITS? Let's start with an historical perspective.