described ITS as tutoring systems thathave both an outer loop and an inner loop. The outer loop selectslearning tasks; it may do so in an adaptive manner (i.e., selectdifferent problem sequences for different students) based on thesystem’s assessment of each individual student’s strengths andweaknesses with respect to the targeted learning objectives. Theinner loop elicits steps within each task (e.g., problem-solvingsteps) and provides guidance with respect to these steps, typicallyin the form of feedback, hints, or error messages. In this regard,CAI, CBT, and Web-based homework are different from ITS inthat they lack an inner loop (VanLehn, 2006).