Michael Yudelson

Individualized Bayesian Knowledge Tracing Models

Bayesian Knowledge Tracing (BKT)[1] is a user modeling method extensively used in the area of Intelligent Tutoring Systems. In the standard BKT implementation, there are only skill-specific parameters. However, a large body of research strongly suggests that student-specific variability in the data, when accounted for, could enhance model accuracy [5,6,8]. In this work, we revisit the problem of introducing student-specific parameters into BKT on a larger scale. We show that student-specific parameters lead to a tangible improvement when predicting the data of unseen students, and that parameterizing students’ speed of learning is more beneficial than parameterizing a priori knowledge.

Addictive links: the motivational value of adaptive link annotation

Adaptive link annotation is a popular adaptive navigation support technology. Empirical studies of adaptive annotation in the educational context have demonstrated that it can help students to acquire knowledge faster, improve learning outcomes, reduce navigational overhead, and encourage non-sequential navigation. In this paper, we present our exploration of a lesser known effect of adaptive annotation, its ability to significantly increase students’ motivation to work with non-mandatory educational content. We explored this effect and confirmed its significance in the context of two different adaptive hypermedia systems. The paper presents and discusses the results of our work.

A User Modeling Server for Contemporary Adaptive Hypermedia: An Evaluation of the Push Approach to Evidence Propagation

Despite the growing popularity of user modeling servers, little attention has been paid to optimizing and evaluating the performance of these servers. We argue that implementation issues and their influence on server performance should become the central focus of the user modeling community, since there is a sharply increasing real-life load on user modeling servers, This paper focuses on a specific implementation-level aspect of user modeling servers --- the choice of pushor pullapproaches to evidence propagation. We present a new push-based implementation of our user modeling server CUMULATE and compare its performance with the performance of the original pull-based CUMULATE server.

From WebEx to NavEx: Interactive Access to Annotated Program Examples

This paper reviews our work on providing students interactive access to annotated program examples. We review our experience with WebEx, the system that allows students to explore examples line by line. After that we present NavEx, an adaptive environment for accessing interactive programming examples. NavEx enhances WebEx with a specific kind of adaptive navigation support known as adaptive annotation. The classroom study of NavEx discovered that adaptive navigation support can visibly increase student motivation to work with nonmandatory educational content. NavEx boosted the overall amount of work done and the average length of a session. In addition, various features of NavEx were highly regarded by the students.

An open integrated exploratorium for database courses

In this paper, we present an open architecture that combines different SQL learning tools in an integrated Exploratorium for database courses. The integrated Exploratorium provides a unique learning environment that allows database students to take complimentary advantages of multiple advanced learning tools.

Addictive links: the motivational value of adaptive link annotation in educational hypermedia

Adaptive link annotation is a popular adaptive navigation support technology. Empirical studies of adaptive annotation in the educational context have demonstrated that it can help students to acquire knowledge faster, improve learning outcome, reduce navigation overhead, and encourage non-sequential navigation. In this paper we present our study of a rather unknown effect of adaptive annotation, its ability to significantly increase student motivation to work with non-mandatory educational content. We explored this effect and confirmed its significance in the context of two different adaptive hypermedia systems. The paper presents and discusses the results of our work.

Adaptive Knowledge-Based Visualization for Accessing Educational Examples

A number of research teams are working to organize personalized access to the modern repositories of educational resources. The goal of personalized access is to help students locate resources that match their individual goals, interests, and current knowledge. The project presented in this paper is focused on the least explored way of personalized access - adaptive visualization. Here, we present the NavEx ADVISE visualization system, which provides personalized access to a repository of educational examples. The system combines spatial, similarity-based visualization with adaptive annotations of resources. The spatial layout and the adaptive annotations are generated using a knowledge-based indexing of examples with domain concepts

A multifactor approach to student model evaluation

Creating student models for Intelligent Tutoring Systems (ITS) in novel domains is often a difficult task. In this study, we outline a multifactor approach to evaluating models that we developed in order to select an appropriate student model for our medical ITS. The combination of areas under the receiver-operator and precision-recall curves, with residual analysis, proved to be a useful and valid method for model selection. We improved on Bayesian Knowledge Tracing with models that treat help differently from mistakes, model all attempts, differentiate skill classes, and model forgetting. We discuss both the methodology we used and the insights we derived regarding student modeling in this novel domain.

Social navigation for educational digital libraries

Abstract An educational digital library may store a wealth of diverse educational resources targeting different audiences from young schoolchildren to graduate students to school and college teachers. With the growth of the volume and the diversity of the library, it becomes increasingly difficult for the users to find resources, which are relevant to their age, educational needs, and personal interests. Social navigation techniques could provide valuable help in this context guiding users to the most useful information. Social navigation works by processing traces of past user behavior and using the assembled “collective wisdom” to guide future users. The paper reports our work on the design of social navigation infrastructure for Ensemble, a major educational digital library. We present the organization of both sides of the social navigation process: how social wisdom is collected and how it can be used to guide portal users to valuable resources. We also report the results of our most recent evaluation of the social navigation infrastructure.

Semantic Integration of Adaptive Educational Systems

With the growth of adaptive educational systems available to students, integration of these systems is evolving from an interesting research problem into an important practical task. One of the challenges that needs to be addressed is the development of mechanisms for student model integration. The architectural principles and representation technologies employed by adaptive educational systems define the applicability of a particular integration approach. This chapter reviews the existing mechanisms and details one of them: the evidence integration.