IBM’s Watson platform has done a number of remarkable things since its inception. Robots in retail stores are now powered by Watson, as are virtual assistants, and (of course) intelligent chatbots. If you aren’t farmilar with it, Watson gives robots and virtual platforms the ability to understand, learn, sense, and experience.

And prank. Pranking works too.

Case in point: Ahshok Goel, a professor at Georgia Institute of Technology has just revealed that he has been employing a robot as one of his teaching assistants. “Jill Watson” has been doing regular TA work for Goel, answering students questions in a forum, reminding students of upcoming important dates over email—and all of this in a way that was so human, students never realized that they were talking to a robot.

To train the robot, Georgia Tech researchers exposed Jill to over 40,000 postings in the discussion forum “Piazza,” and taught her to use previous responses to reply to related questions.

“Our TAs are getting bogged down answering routine questions,” Goel states, and adds that students often post a staggering 10,000 messages a semester. he asserts that, within a year, Watson will be able to answer 40% of all the students’ questions, which will allow the humans to tackle more complex technical questions.