ly engaging. Instead of being passive recipients of
knowledge, learners actively use and construct their
knowledge through dialogue. They must formulate
their own responses instead of selecting from mul-
tiple-choice responses that the learning system
presents to them. As dialogue-based systems
become more widespread, we predict that they will
result in higher levels of engagement, higher levels
of learning, and better retention in learning pro-
The challenge for agent developers now is to lever-
age dialogue technologies to support multimodal dia-
logue and to promote better learning. Whereas natu-
ral-language-processing services focus solely on text
Figure 5. A Combination of Agents Used in VCATS.
VCAT Virtual Coach (left) and Virtual Role-Play (right). ©Alelo Inc. Reproduced with permission.
Figure 6. Enskill Simulated Dialogue with Pedagogical Agents.
© Alelo Inc. Reproduced with permission.