What Do Human Tutors Do?

People teaching an agent or robot might use the same methods that they use when tutoring a human student. Because teaching agents and robots is a central topic of this Ernst Strüngmann Forum, this chapter reviews research that characterizes human tutoring. Most of this research was done to improve the design of computer-based tutoring systems, which were assumed to be inferior to human tutors. However, it turns out that human tutors and a certain class of tutoring systems actually behave quite similarly, and their effectiveness is about the same. This chapter begins with a description of prototypical human tutoring behavior before discussing some common hypotheses about human tutoring behavior, which turn out to be unsupported by studies. It concludes with an attempt to synthesize these descriptions and apply them to the goals set forth at this Forum.