The document discusses learner modeling and adaptation in the Math-Bridge intelligent tutoring system. It describes the main components of the system including the learner model, domain model, and pedagogical model. It provides details on how the learner model is updated based on evidence from student interactions and how this information is used to adapt instruction by selecting appropriate content and sequencing. The system aims to personalize course generation and annotation based on the individual student model.
7. Intelligent Adaptive e-Learning System:
Main Components
Instructional
Content
Interaction
0..1..1
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1..
Domain
Model
!
!
!
Learner
Model
Pedagogical
Model
Adaptation
Me t a d a t a
9. Rich continuos stream of learning data
❖ Any interaction of the student with Math-Bridge causes
an event in the system logs;!
❖ More than 30 types of events (e.g., system login/logout,
course started/finished, exercise started/finished, etc.);!
❖ More than 50 attributes (e.g., for the exerciseStep event:
time, user, session, courseId, successRate, metadataText,
userInputDelay, userInputText,…);
14. Martin Homik 5th Sakai Conference 2006, Vancouver
!14
Knowledge Representation
D
S
EX
P
T
S S
S
isA
D
D T
XE
Definition
E
Symbol
Example
Theorem
ProofExercise
X
forfor
forforfor
D D
for counter
P
for
S S
for depends on
depends on
Abstract Layer
Content Layer
Satellite Layer
15. OMDoc
❖ All content and its metadata, are
represented in OMDoc!
❖ OMDoc is an XML dialect developed for
math documents !
❖ Formulas are written in OpenMath!
❖ OpenMath is an extensible standard for
representing the semantics of mathematical
objects
<definition id="c6s1p4_Th2_def_monoid" for="c6s1p4_monoid„
<metadata>
<depends-on>
<ref theory="cp1_Th3" name="structure" />
</depends-on>
<Title xml:lang="en">Definition of a monoid</Title>
</metadata>
<CMP xml:lang="en" format="omtext">
A monoid is a <ref xref="cp1_Th3_def_structure"> structure </ref>
<OMOBJ>
<OMS cd="elementary" name="ordered-triple"/>
<OMV name="M"/> <OMS cd="cp4_Th2" name="times"/> <OMS cd="cp4_Th2" name="unit"/>
</OMOBJ>
in which
<OMOBJ>
<OMS cd="elementary" name="ordered-pair"/>
<OMV name="M"/> <OMS cd="cp4_Th2" name="times"/>
</OMOBJ>
is a semi-group
with <ref xref="c6s1p3_Th2_def_unit">e</ref>
<OMOBJ xmlns="http://www.openmath.org/OpenMath">
<OMS cd="cp4_Th2" name="unit"/>
</OMOBJ>.
</CMP>
<FMP><OMOBJ> ... </OMOBJ></FMP>
</definition>
Definition of
a Monoid
19. Updates
❖ Direct evidence - individual events for 1 concept, 1
process!
❖ Indirect evidence - propagation!
❖ Intra-Concept: across competencies!
❖ Inter-Concept: prerequisite, for
20. Amplitude of the update
❖ IRT:
psychometric
theory for
testing!
❖ Used
successfully
since 20+
years
21. IRT Usage
❖ Pool of calibrated items with known ICC!
❖ Logistic function (difficulty, discrimination, guess)!
❖ Idea: Measure latent trait 𝞱!
❖ Administer sequence of test items!
❖ 𝞱 uncovered by responses to items
22. IRT vs. MthBridge—IRT
Propoer IRT MathBridge—IRT
ICC Empirical Theoretical
Input
Item Response
Sequence
Sparse
Evidences
Answers Dichotomous Continuous
Difficulty Single factor
Difficulty/
Competency
Independence
Items are
independent of each
other
Exercises are often
related
Learning
No learning between
or during
assessment
Learning is essential
for Math-Bridge
23. Belief Masses
❖ Round achievement to {1,0}!
❖ if r=1:
m(H(b)) = P(correct | 𝞱 =b)!
❖ if r=0:
m(H(b)) = 1-P(correct | 𝞱 =b)!
!
❖ restrict updated hypotheses
to Information Radius
interval: [irtdiff ±δ]
𝞱
p(correct)