Now Goel is forming a business to bring the chatbot to the wider world of education. While he doesn't foresee the chatbot replacing teaching assistants or professors, he expects the chatbot's question-answering abilities to be an invaluable asset for massive online open courses, where students often drop out and generally don't receive the chance to engage with a human instructor. With more human-like interaction, Goel expects online learning could become more appealing to students and lead to better educational outcomes.

"To me this is a grand challenge," Goel said. "Education is such a huge priority for the entire human race."

At the start of this semester Goel provided his students with a list of nine teaching assistants, including Jill, the automated question and answering service Goel developed with the help of some of his students and IBM.

Goel and his teaching assistants receive more than 10,000 questions a semester from students on the course's online forum. Sometimes the same questions are asked again and again. Last year he began to wonder if he could automate the burden of answering so many repetitive questions.

As Goel looked for a technology that could help, he settled on IBM Watson, which he had used for several other projects. Watson, an artificial intelligence system, was designed to answer questions, so it seemed like a strong fit.