Computerized Tutors

Source: NYTimes, Sep 2012

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.

… the only way to close the persistent “achievement gap” between white and minority, high- and low-income students was to offer universal tutoring — to give each student access to his or her own Cristina Lindquist. While hiring a human tutor for every child would be prohibitively expensive, the right computer program could make this possible.

… researchers who, spurred by the 1984 Bloom study, set out to discover what tutors do that is so helpful to student learning. First and foremost, they concluded, tutors provide immediate feedback: they let students know whether what they’re doing is right or wrong. Such responsiveness keeps students on track, preventing them from wandering down “garden paths” of unproductive reasoning.

The second important service tutors provide, researchers discovered, is guiding students’ efforts, offering nudges in the right direction. ASSISTments provides this, too, in the form of a “hint” button. Tyler chose not to use it that evening, but if he had, he would have been given a series of clues to the right answer, “scaffolded” to support his own problem-solving efforts. For the answer “5-3x,” the computer responded: “You need to take a closer look at your signs. Notice there is a minus in front of the ‘y.’ ”

Dealing with emotion — helping students regulate their feelings, quelling frustration and rousing flagging morale — is the third important function that human tutors fulfill.

“The first thing we had to do is identify which emotions are important in tutoring, and we found that there are three that really matter: boredom, frustration and confusion,” D’Mello said.

Once the student’s feelings are identified, the thinking goes, the computerized tutor could adjust accordingly — giving the bored student more challenging questions or reviewing fundamentals with the student who is confused.

The aim, he says, is to endow his computerized tutor “with the qualities of humans that help other humans learn.”

… so far, the small number of preliminary, peer-reviewed studies he has conducted on his program support its value: one randomized controlled trial found that the use of the computerized tutor improved students’ performance in math by the equivalent of a full letter grade over the performance of pupils who used paper and pencil to do their homework.

Human teachers and tutors are susceptible to what cognitive scientists call the “expert blind spot” — once we’ve mastered a body of knowledge, it’s hard to imagine what novices don’t know — but computers have no such mental block. Highlighting “common wrong answers” allows Thienpont to address shared misconceptions without putting any one student on the spot.

Unlike the proprietary software sold by Carnegie Learning, or by education-technology giants like Pearson, ASSISTments was designed to be modified by teachers and students, in a process Heffernan likens to the crowd-sourcing that created Wikipedia. His latest inspiration is to add a button to each page of ASSISTments that will allow students to access a Web page where they can get more information about, say, a relevant math concept. Heffernan and his W.P.I. colleagues are now developing a system of vetting and ranking the thousands of math-related sites on the Internet.

For all his ambition, Heffernan acknowledges that this technology has limits. He has a motto: “Let computers do what computers are good at, and people do what people are good at.”

Computers excel in following a precise plan of instruction. A computer never gets impatient or annoyed. But it never gets excited or enthusiastic either. Nor can a computer guide a student through an open-ended exploration of literature or history. It’s no accident that ASSISTments and other computerized tutoring systems have focused primarily on math, a subject suited to computers’ binary language. While a computer can emulate, and in some ways exceed, the abilities of a human teacher, it will not replace her.

Rather, it’s the emerging hybrid of human and computer instruction — not either one alone — that may well transform education.


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