Neil Heffernan was listening to his fiancée, Cristina Lindquist, tutor one of her students in mathematics when he had an idea. Heffernan was a graduate student in computer science, and by this point — the summer of 1997 — he had been working for two years with researchers at Carnegie Mellon University on developing computer software to help students improve their skills. But he had come to believe that the programs did little to assist their users. They were built on elaborate theories of the student mind — attempts to simulate the learning brain. Then it dawned on him: what was missing from the programs was the interventions teachers made to promote and accelerate learning. Why not model a computer program on a human tutor like Lindquist?
The Education Issue
The Machines Are Taking Over
By ANNIE MURPHY PAUL
Published: September 14, 2012
Over the next few months, Heffernan videotaped Lindquist, who taught math to middle-school students, as she tutored, transcribing the sessions word for word, hoping to isolate what made her a successful teacher. A look at the transcripts suggests the difficulties he faced. Lindquist’s tutoring sessions were highly interactive: a single hour might contain more than 400 lines of dialogue. She asked lots of questions and probed her student’s answers. She came up with examples based on the student’s own experiences. She began sentences, and her student completed them. Their dialogue was anything but formulaic.
Lindquist: Do you know how to calculate average driving speed?
Student: I think so, but I forget.
Lindquist: Well, average speed — as your mom drove you here, did she drive the same speed the whole time?
Student: No.
Lindquist: But she did have an average speed. How do you think you calculate the average speed?
Student: It would be hours divided by 55 miles.
Lindquist: Which way is it? It’s miles per hour. So which way do you divide?
Student: It would be 55 miles divided by hours.
As the session continued, Lindquist gestured, pointed, made eye contact, modulated her voice. “Cruising!” she exclaimed, after the student answered three questions in a row correctly. “Did you see how I had to stop and think?” she inquired, modeling how to solve a problem. “I can see you’re getting tired,” she commented sympathetically near the end of the session. How could a computer program ever approximate this?
In a 1984 paper that is regarded as a classic of educational psychology, Benjamin Bloom, a professor at the University of Chicago, showed that being tutored is the most effective way to learn, vastly superior to being taught in a classroom. The experiments headed by Bloom randomly assigned fourth-, fifth- and eighth-grade students to classes of about 30 pupils per teacher, or to one-on-one tutoring. Children tutored individually performed two standard deviations better than children who received conventional classroom instruction — a huge difference.
Affluent American parents have since come to see the disparity Bloom identified as a golden opportunity, and tutoring has ballooned into a $5 billion industry. Among middle- and high-school students enrolled in New York City’s elite schools, tutoring is a common practice, and the most sought-after tutors can charge as much as $400 an hour.
But what of the pupils who could most benefit from tutoring — poor, urban, minority? Bloom had hoped that traditional teaching could eventually be made as effective as tutoring. But Heffernan was doubtful. He knew firsthand what it was like to grapple with the challenges of the classroom. After graduating from Amherst College, he joined Teach for America and was placed in an inner-city middle school in Baltimore. Some of his classes had as many as 40 students, all of them performing well below grade level. Discipline was a constant problem. Heffernan claims he set a school record for the number of students sent to the principal’s office. “I could barely control the class, let alone help each student,” Heffernan told me. “I wasn’t ever going to make a dent in this country’s educational problems by teaching just a few classes of students at a time.”
This article has been revised to reflect the following correction:
Correction: September 30, 2012
An article on Sept. 16 about computerized tutoring referred incorrectly to aspects of an initiative in Maine that provides students with laptops. Only seventh and eighth graders are supplied laptop computers, not all students. The students are given the laptops for the school year; they do not own them.
A version of this article appeared in print on September 16, 2012, on page MM50 of the Sunday Magazine with the headline: The Machines Are Taking Over.
