A computer-based system, called the FLOW system, was used in experimental studies of human learning. The student learns a simple computer language from printed instructions and can run his programs interactively on the FLOW system. An automated tutor simulates a human tutor who watches over the student and gives help when the student has difficulties. The system also records detailed protocols of the interactions among the student, the computer, the automated tutor, and the human tutor for later analysis. (Author)