Robots are becoming classroom tutors. But will they make the grade?

Pondering a tablet screen displaying a town scene, a pre-K student tilts her head to the side and taps her lip thoughtfully.

“What are we trying to find?” asks the plush, red and blue robot called Tega that’s perched on the desk beside the girl. The bot resembles a teddy bear–sized Furby.

“We are trying to find lavender-colored stuff,” the girl explains. Lavender is a new...[link]