Symbolic Systems Forum - Heather Pon-Barry (M.S. Candidate), Symbolic Systems Program

Heather Pon-Barry (M.S. Candidate), Symbolic Systems Program, "In Search of Bloom's Missing Sigma"

ABSTRACT:

In 1984, Benjamin Bloom reported that students who interacted with expert human tutors yielded test scores two standard deviations above those who received ordinary classroom instruction. Since then, this "2 sigma" effect has been commonly used as the gold-standard for measuring instructional effectiveness. Researchers in various fields have been building intelligent tutoring systems (ITSs) for over three decades--with a recent trend towards dialogue-based tutoring systems--yet currently, the best ITSs report learning gains of only 1 standard deviation above classroom instruction. Naturally this leads one to wonder, what happened to the second sigma? What is it that expert human tutors do that makes their interaction so effective? At CSLI, we have been developing the first Spoken Conversational Tutor (SCoT) under the hypothesis that spoken dialogue might account for (part of) Bloom's missing sigma. I have been exploring the idea that certain features of the student's language can be used to help the tutor present information at an appropriate level of granularity. Adapting to their behavior in this way should make it easier for the student to build a clear mental representation of what is being discussed, and thus facilitate self-reflection. In this talk, I will present the work I have been doing to test these hypotheses, and describe how they have influenced the architecture of the tutorial component I am designing.