The student model of the LEAP intelligent tutoring system

This research was performed at U S WEST. LEAP is a coached practice environment that optimizes the learning process by maintaining and consulting a detailed student model. LEAP calculates a student model score for every action, exercise, and topic the stud

The Student Model of the LEAP Intelligent Tutoring System

Frank Linton**

The MITRE Corporation202 Burlington RoadBedford MA 01730 USA

linton@http://www.77cn.com.cn

Brigham Bell

U S WEST

Advanced TechnologiesBoulder CO 80303 USAbbell@http://www.77cn.com.cn

Charles Bloom**

NYNEX

Science and TechnologyWhite Plains NY 10604 USA

cbloom@http://www.77cn.com.cn

Abstract

LEAP is a coached practice environment that optimizesthe learning process by maintaining and consulting adetailed student model. LEAP calculates a student modelscore for every action, exercise, and topic the studenttries, then uses the scores both to provide feedback tothe student and to select topics, exercises and actions forthe student to practice. Using the student model to focuspractice means exercises can be realistic and complexinstead of artificial and simple, thereby reducing prob-lems of motivation and transfer, and increasing LEAP’ssimilarity to apprenticeship learning. To optimizelearning, LEAP selects exercises relevant to the currentinstructional topic, and modifies the selected exercisesto focus trainees’ effort. Within an exercise, traineespractice material they are currently attempting to learn,review material they have already learned, and observematerial that they are not yet prepared to learn. The stu-dent model is updated after each pass through an exer-cise, enabling LEAP to continually refocus its instruc-tion as trainees learn or forget.

Introduction

If an intelligent tutor is to optimize the learning process,it must focus the student's effort on acquiring those skillslying within the narrow shifting zone piding the already-learned skills from the not-yet-learned ones. It musteliminate from the students’ activities those skills theyhave already learned and have no further need to study, andthose they are not yet prepared to learn. The information atutor needs to optimize the learning process can comeonly from a detailed student model.

LEAP (Learn, Explore, and Practice) is a coached prac-tice environment (Lesgold, Eggan, Katz, & Rao 1992) fortraining customer service representatives for a telephonecompany (U S WEST). LEAP contains sufficient domainknowledge for eight to sixteen hours of training on thetopic of voice messaging sales and service. LEAP hasbeen tested with twenty-nine trainees in one-day sessions.The LEAP tutor is described more fully in Linton (1995)

** This research was performed at U S WEST.

and in Bloom, Bell, Meiskey, Sparks, Dooley, & Linton(1995).

LEAP's student model scores every student action, exer-cise, and topic the student tries. LEAP then uses thescores both to provide feedback to the student and to selecttopics, exercises and actions for the student to http://www.77cn.com.cning the student model as a basis for selecting andmodifying exercises has two important effects: first, exer-cises can be designed to be realistic instead of being artifi-cially simplified to be within the student's ability. Realis-tic exercises address the critical issues of motivation(Lepper, Woolverton, Mumme, & Gurtner 1993; Keller1983), and transfer (Larkin 1989), and increase LEAP’ssimilarity to apprenticeship learning (Suchman 1987;Lave & Wenger 1991). Second, LEAP's ability to selectand modify exercises based on an instructional strategy andthe state of the student model helps optimize learning.LEAP selects an exercise based on the material it containsthat is relevant to the current topic. LEAP then modifiesthe selected exercise so that trainees practice material theyare currently attempting to learn, review material theyhave already learned, and observe material that they are notyet ready to learn. In brief, LEAP takes advantage of thestudent model to provide realistic exercises and to focusinstruction within each exercise.

The following sections of the paper first describe thetraining task, second provide an overview of the tutor,third lay out the representation of domain and tutoringknowledge, fourth detail the student model, fifth, explainhow the student model is used in tutoring decisions, andfinally, compare LEAP's student model with others.

1. The Training Task

LEAP’s trainees are customer service representatives, orreps, for U S WEST, a regional telephone company. Repssell U S WEST’s products and services. Currently, U SWEST has several thousand employees in customer serv-ice or related jobs, and hires or transfers several hundred

This research was performed at U S WEST. LEAP is a coached practice environment that optimizes the learning process by maintaining and consulting a detailed student model. LEAP calculates a student model score for every action, exercise, and topic the stud

employees into customer service jobs every year. Thetraining need is twofold: to train new employees, and tocontinuously update the knowledge and skills of existingreps as product and service changes are made.

The rep’s job is complex. First, service representativesdeal with a vast amount of frequently-updated informationabout the products and services available. Second, repsmust be careful to comply with all regulations, since thecompany is highly regulated at both the federal and statelevels. Third, reps must construct a conversation with acustomer while simultaneously inputting and retrievinginformation from various databases.

Current training, ten weeks of classroom instructionwith a six to one student to teacher ratio, is expensive.Trainees spend about a quarter of their time practicingservice rep skills by doing role-plays with each otherwhile the instructor obser …… 此处隐藏：33452字，全部文档内容请下载后查看。喜欢就下载吧 ……