Download Cognitive Tutors: Bringing advanced cognitive research to the

This is the 5th Annual PSLC Summer
School
• 9th overall
– ITS was focus in
2001 to 2004
• Goals:
– Learning science &
technology
concepts
– Hands-on project
you present on Fri
1
Studying and achieving robust
learning with PSLC resources
Ken Koedinger
HCI & Psychology
CMU Director of PSLC
2
Vision for PSLC
• Why?
“rigorous, sustained scientific
research in education” (NRC, 2002)
Chasm between science & practice
Indicators: Ed achievement gaps persist,
Low hit rate of randomized controlled trials (<.2!)
• Underlying problem:
Many ideas,
too little sound scientific foundation
• Need: Basic research studies in the field
=> PSLC Purpose: Identify the conditions that
cause robust student learning
– Field-based rigorous science
– Leverage cognitive & computational theory, educational
technologies
3
The Setting & Inspiration
• Rich tradition of research on Learning and
Instruction at CMU & University of Pittsburgh
– Basic Cognitive Science from CS & Psych collab
– Learning in academic domains
• Science, math, literacy, history …
• Many studies, but not enough cross talk
– Theory inspired intelligent tutors:
• Andes physics tutor in college classrooms
• Cognitive Algebra Tutor in 2500+ US schools
• A key PSLC inspiration: Educational technology as
research platform to launch new learning science
4
Overview
Next
• Background
– Intelligent Tutoring Systems
– Cognitive Task Analysis
• PSLC Methods, Resources, & Theory
– In vivo experimentation
– LearnLab courses & enabling technologies
– Theoretical framework
• Summary & Future
5
PSLC is about much more
than Intelligent Tutors
But tutors & course
evaluations were a key
inspiration
Quick review …
6
Past Success: Intelligent Tutors Bring
Learning Science
to Schools!
• Intelligent tutoring
systems
– Automated 1:1 tutor
– Artificial Intelligence
– Cognitive Psychology
• Andes: College Physics
Tutor
– Replaces homework
Students: model problems with
diagrams, graphs, equations
Tutor: feedback, help,
reflective dialog
• Algebra Cognitive Tutor
– Part of complete course
7
b
Cognitive Tutor Approach
Research base
Cognitive
Psychology
Artificial
Intelligence
Cognitive
Tutor
Technology
Curriculum Content
Math Instructors
Math Educators
NCTM Standards
Cognitive Tutors
Algebra I
Equation
Solver
Geometry
Algebra II
Cognitive Tutor Technology
• Cognitive Model: A system that can solve problems in
the various ways students can
Strategy 1:
Strategy 2:
Misconception:
IF the goal is
THEN rewrite
IF the goal is
THEN rewrite
IF the goal is
THEN rewrite
to solve a(bx+c) = d
this as abx + ac = d
to solve a(bx+c) = d
this as bx + c = d/a
to solve a(bx+c) = d
this as abx + c = d
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Cognitive Tutor Technology
• Cognitive Model: A system that can solve problems in
the various ways students can
3(2x - 5) = 9
If goal is solve a(bx+c) = d
Then rewrite as abx + ac = d
If goal is solve a(bx+c) = d
Then rewrite as abx + c = d
If goal is solve a(bx+c) = d
Then rewrite as bx+c = d/a
6x - 15 = 9
2x - 5 = 3
6x - 5 = 9
• Model Tracing: Follows student through their individual
approach to a problem -> context-sensitive instruction
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Cognitive Tutor Technology
• Cognitive Model: A system that can solve problems in
the various ways students can
3(2x - 5) = 9
If goal is solve a(bx+c) = d
Then rewrite as abx + ac = d
If goal is solve a(bx+c) = d
Then rewrite as abx + c = d
Hint message: “Distribute a
across the parentheses.”
Known? = 85% chance
6x - 15 = 9
Bug message: “You need to
multiply c by a also.”
Known? = 45%
2x - 5 = 3
6x - 5 = 9
• Model Tracing: Follows student through their individual
approach to a problem -> context-sensitive instruction
• Knowledge Tracing: Assesses student's knowledge
growth -> individualized activity selection and pacing
11
Cognitive Tutor Course
Development Process
1.
2.
3.
4.
Client & problem identification
Identify the target task & “interface”
Perform Cognitive Task Analysis (CTA)
Create Cognitive Model & Tutor
a. Enhance interface based on CTA
b. Create Cognitive Model based on CTA
c. Build a curriculum based on CTA
5. Pilot & Parametric Studies
6. Classroom Evaluation & Dissemination
12
b
Cognitive Tutor Approach
Research base
Cognitive
Psychology
Artificial
Intelligence
Cognitive
Tutor
Technology
Curriculum Content
Math Instructors
Math Educators
NCTM Standards
Cognitive Tutors
Algebra I
Equation
Solver
Geometry
Algebra II
Difficulty Factors Assessment:
Discovering What is Hard for Students to Learn
Which problem type is most difficult for Algebra students?
Story Problem
As a waiter, Ted gets $6 per hour. One night he made $66 in
tips and earned a total of $81.90. How many hours did Ted
work?
Word Problem
Starting with some number, if I multiply it by 6 and then add
66, I get 81.90. What number did I start with?
Equation
x * 6 + 66 = 81.90
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Algebra Student Results:
Story Problems are Easier!
Percent Correct
80%
70%
61%
60%
42%
40%
20%
0%
Story
Word
Equation
Problem Representation
Koedinger, & Nathan, (2004). The real story behind story problems: Effects of representations
on quantitative reasoning. The Journal of the Learning Sciences.
Koedinger, Alibali, & Nathan (2008). Trade-offs between grounded and abstract representations:
Evidence from algebra problem solving. Cognitive Science.
15
Expert Blind Spot:
Expertise can impair judgment of student
difficulties
100
90
80
% making
correct
ranking
(equations
hardest)
70
60
50
40
30
20
10
0
Elementary
Teachers
Middle
School
Teachers
High School
Teachers
Nathan , M. J. & Koedinge r, K. R. (2000). An inve stigation of teacher s' beliefs of
students' algebra deve lopment. Cognition and Instruction, 18(2), 207-235
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“The Student Is Not Like Me”
• To avoid your expert blindspot,
remember the mantra:
“The Student Is Not Like Me”
• Perform Cognitive Task Analysis
to find out what students are like
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Cognitive Tutor Course
Development Process
1.
2.
3.
4.
Client & problem identification
Identify the target task & “interface”
Perform Cognitive Task Analysis (CTA)
Create Cognitive Model & Tutor
a. Enhance interface based on CTA
b. Create Cognitive Model based on CTA
c. Build a curriculum based on CTA
5. Pilot & Parametric Studies
6. Classroom Evaluation & Dissemination
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Tutors make a significant difference
in improving student learning!
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• Andes: College Physics
Tutor
– Field studies: Significant
improvements in
student learning
• Algebra Cognitive Tutor
– 10+ full year field
studies: improvements
on problem solving,
concepts, basic skills
– Regularly used in 1000s
of schools by 100,000s
of students!!
70
65
Control
Andes
60
55
50
2000
60
2001
2002
2003
Traditional Algebra Course
50
Cognitive Tutor Algebra
40
30
20
10
0
Iowa
SAT subset
Problem
Solving
Representations
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President Obama on
Intelligent Tutoring
Systems!
“[W]e will devote more than three percent of our GDP to
research and development. …. Just think what this
will allow us to accomplish: solar cells as cheap as
paint, and green buildings that produce all of the
energy they consume; learning software as effective as
a personal tutor; prosthetics so advanced that you
could play the piano again; an expansion of the
frontiers of human knowledge about ourselves and
world the around us. We can do this.”
http://my.barackobama.com/page/community/post/amy
hamblin/gGxW3n
20
Prior achievement:
Intelligent Tutoring Systems
bring learning science to schools
A key PSLC inspiration:
Educational technology as
research platform to generate
new learning science
21
Overview
• Background
– Intelligent Tutoring Systems
– Cognitive Task Analysis
Next
• PSLC Methods, Resources, & Theory
– In vivo experimentation
– LearnLab courses & enabling technologies
– Theoretical framework
• Summary & Future
22
PSLC Statement of Purpose
Leverage cognitive and
computational theory to
identify the instructional
conditions that cause
robust student learning.
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What is Robust Learning?
• Robust Learning is learning that
– transfers to novel tasks
– retained over the long term, and/or
– accelerates future learning
• Robust learning requires that students develop
both
– conceptual understanding & sense-making skills
– procedural fluency with basic foundational skills
24
PSLC Statement of Purpose
Leverage cognitive and
computational theory to
identify the instructional
conditions that cause
robust student learning.
25
In Vivo Experiments
Principle-testing laboratory
quality in real classrooms
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In Vivo Experimentation
What is tested?
Methodology
– Instructional solution vs.
causal principle
Instructional
solution
Lab
Methodology features:
• What is tested?
Causal
principle
Lab
experiments
• Where & who?
• How?
– Treatment only vs.
Treatment + control
• Generalizing conclusions:
– Ecological validity: What
instructional activities
work in real classrooms?
– Internal validity: What
causal mechanisms
explain & predict?
Classroom
– Lab vs. classroom
Design
research
&
field trials
27
In Vivo Experimentation
What is tested?
Methodology
– Instructional solution vs.
causal principle
Instructional
solution
Lab
Methodology features:
• What is tested?
Causal
principle
Lab
experiments
• Where & who?
• How?
– Treatment only vs.
Treatment + control
• Generalizing conclusions:
– Ecological validity: What
instructional activities
work in real classrooms?
– Internal validity: What
causal mechanisms
explain & predict?
Classroom
– Lab vs. classroom
Design
research
&
field trials
28
In Vivo Experimentation
What is tested?
Methodology
– Instructional solution vs.
causal principle
Instructional
solution
Lab
Methodology features:
• What is tested?
Causal
principle
Lab
experiments
• Where & who?
• How?
– Treatment only vs.
Treatment + control
• Generalizing conclusions:
– Ecological validity: What
instructional activities
work in real classrooms?
– Internal validity: What
causal mechanisms
explain & predict?
Classroom
– Lab vs. classroom
Design
research
&
field trials
In Vivo
learning
experiments
29
LearnLab
A Facility for Principle-Testing
Experiments in Classrooms
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LearnLab courses at
K12 & College Sites
• 6+ cyber-enabled courses:
Chemistry, Physics,
Algebra, Geometry,
Chinese, English
• Data collection
– Students do home/lab work
on tutors, vlab, OLI, …
– Log data, questionnaires,
tests  DataShop
Researchers
Schools
Learn
Lab
Chemistry virtual lab
Physics intelligent tutor
REAP vocabolary tutor
31
PSLC Enabling Technologies
• Tools for developing instruction & experiments
– CTAT (cognitive tutoring systems)
• SimStudent (generalizing an example-tracing tutor)
– OLI (learning management)
– TuTalk (natural language dialogue)
– REAP (authentic texts)
• Tools for data analysis
– DataShop
– TagHelper
32
LearnLab Products
Infrastructure created and highly used
• LearnLab courses have supported over
150 in vivo experiments
• Established DataShop: A vast open data
repository & associated tools
– 110,000 student hours of data
• 21 million transactions at ~15 second intervals
– New data analysis & modeling algorithms
– 67 papers, >35 are secondary data analysis not
possible without DataShop
33
PSLC Statement of Purpose
Leverage cognitive and
computational theory to
identify the instructional
conditions that cause
robust student learning.
34
Typical Instructional Study
• Compare effects of 2 instructional conditions in lab
• Pre- & post-test similar to tasks in instruction
Instruction
Expert
Novice
Learning
Pre-test
Post-test
35
PSLC Studies
• Macro: Measures of robust learning
• Micro analysis: knowledge, learning, interactions
• Studies run in vivo: social & motivational context
Social
context of
classroom
Instruction
Expert
Novice
Knowledge:
Shallow,
perceptual
Instructional Events
Learning
Knowledge:
Deep,
conceptual,
fluent
Assessment
Events
Pre-test
Post-test Long-term retention,
Post-test:
transfer, accelerated future learning
36
Develop a research-based,
but practical framework
• Theoretical framework key goals
– Support reliable generalization from empirical
studies to guide design of effective ed practices
Two levels of theorizing:
• Macro level
– What instructional principles explain how changes in the
instructional environment cause changes in robust
learning?
• Micro level
– Can learning be explained in terms of what knowledge
components are acquired at individual learning events?
37
Example study at macro level:
Hausmann & VanLehn 2007
• Research question
– Should instruction provide explanations and/or elicit
“self-explanations” from students?
• Study design
– All students see 3 examples & 3 problems
• Examples: Watch video of expert solving problem
• Problems: Solve in the Andes intelligent tutor
– Treatment variables:
• Videos include justifications for steps or do not
• Students are prompted to “self-explain” or paraphrase
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Paraphrase
Explan
Selfexplain
X
No
explan
39
Paraphrase
Selfexplain
Explan
No
explan
X
40
Self-explanations =>
greater robust learning
• Transfer to new electricity
homework problems
Paraphrase, Paraphrase, Self-explain, Self-explain,
With just. Without just. With just. Without just.
0
(hints+errors) / steps
• Justifications: no effect!
• Immediate test on
electricity problems:
Paraphrase, Paraphrase, Self-explain, Self-explain,
With just. Without just. With just. Without just.
0.2
0.4
0.90
0.98
0.67
0.67
0.45
0.4
0.6
0.8
1
1.2
• Instruction on electricity unit =>
accelerated future learning of
magnetism!
Paraphrase, Paraphrase, Self-explain, Self-explain,
With just. Without just. With just. Without just.
0
0.8
1.2
0.37
0.2
0.6
1
1.04
1.4
(hints+errors) / steps
(hints+errors) / steps
0
0.69
1.17
0.91
0.75
0.68
0.2
0.4
0.6
0.8
1
1.2
1.4
41
Key features of H&V study
• In vivo experiment
– Ran live in 4 physics sections at US Naval
Academy
– Principle-focused: 2x2 single treatment
variations
– Tight control manipulated through
technology
• Use of Andes tutor
=> repeated embedded assessment without
disrupting course
• Data in DataShop (more later)
42
Develop a research-based,
but practical framework
• Theoretical framework key goals
– Support reliable generalization from empirical
studies to guide design of effective ed practices
Two levels of theorizing:
• Macro level
– What instructional principles explain how changes in the
instructional environment cause changes in robust
learning?
• Micro level
– Can learning be explained in terms of what knowledge
components are acquired at individual learning events?
43
Knowledge Components
• Knowledge Component
– A mental structure or process that a learner uses,
alone or in combination with other knowledge
components, to accomplish steps in a task or a
problem-- PSLC Wiki
• Evidence that the Knowledge Component level
functions in learning …
44
Back to H&V study: Micro-analysis
Learning curve for main KC
Self-explanation effect tapers but not to zero
7.00
(hints+errors)/steps
6.00
Instructional
explanation
5.00
4.00
3.00
2.00
Selfexplanation
1.00
0.00
Problem1
Example1
Problem2
Example2
Problem3
Example3
46
PSLC wiki: Principles &
studies that support them
Instructional Principle pages unify across studies
Points to Hausmann’s study page
(and other studies too)
47
PSLC wiki: Principles &
studies that support them
Hausmann’s study description:
With links to concepts in glossary
48
PSLC wiki: Principles &
studies that support them
Self-explanation glossary entry
~200 concepts in glossary
49
Research Highlights
• Synthesizing worked examples &
self-explanation research
– 10+ studies in multiple 4 math & science domains
– New theory: It’s not just cognitive load!
• Examples for deep feature construction,
problems & feedback for shallow feature elimination
This work inspired new question: Does self-explanation enhance
language learning? Experiments in progress …
• Computational modeling of student Learning
– Simulated learning benefits of examples/demonstrations vs.
problem solving (Masuda et al., 2008)
• Theory outcome: problem solving practice is an important source of
negative examples
• Engineering: “programming by tutoring” is more cost-effective than
“programming by demonstration”
– Shallow vs. deep prior knowledge changes learning rate (Matsuda
et al., in press)
50
Research Highlights (cont)
 Computational modeling of instructional assistance
 Assistance formula: Optimal learning (L) depends on
L
right level of assistance
L = P*Sb+(1-P)Fb
P*Sc+(1-P)Fc
Assistance
 Relevant to multiple experimental paradigms & dimensions of
instructional assistance
P
 Direct instruction (worked examples) vs. constructivism (testing effect)
Kirschner, Sweller, & Clark (2006). Why minimal guidance during instruction does not
work: An analysis of the failure of constructivist, discovery, problem-based,
experiential, and inquiry-based teaching. Educational Psychologist
 Concrete manipulatives vs. simple abstractions
Kaminski, Sloutsky, & Heckler (2008). The advantage of learning abstract examples
in learning math. Science.
 Formula provides path to resolve hot debates
51
Research Highlights (cont)
 Synthesis paper on computer tutoring of metacognition
Koedinger, Aleven, Roll, & Baker. (in press). In vivo experiments on whether
supporting metacognition in intelligent tutoring systems yields robust learning.
In Handbook of Metacognition in Education.
 Generalizes results across 7 studies, 3 domains, 4 populations
 Posed new questions about role of motivation
 Lasting effects of metacognitive support
 Computer-based tutoring of self-regulatory learning
 Technologically possible & can have a lasting effect
 Students who used help-seeking tutor demonstrated better
learning skills in later units after support was faded
 Spent 50% more time reading help messages
 Data mining for factors that affect student motivation
 Machine learning to analyze vast student interaction data
from full year math courses (Baker et al., in press a & b)
 Students more engaged on “rich” story problems than standard
 Surprise: Also more engaged on abstract equation exercises!
52
Overview
• Background
– Intelligent Tutoring Systems
– Cognitive Task Analysis
• PSLC Methods, Resources, & Theory
– In vivo experimentation
– LearnLab courses & enabling technologies
– Theoretical framework
• Summary & Future
Next
53
Summary
“rigorous, sustained scientific
research in education” (NRC, 2002)
• Why? Chasm between science & practice
• PSLC Purpose: Identify the conditions that cause
robust student learning
– Field-based rigorous science
– Leverage cognitive & computational theory, educational
technologies
• Results:
Sound evidence & deeper theory behind
principles to bridge chasm
• Impact:
spread use
Principles, methods, tools, & data in wide-
54
Thrusts investigate
overlapping factors
Social
context of
classroom
Novice
Knowledge
Knowledge:
Shallow,
perceptual
Metacognition
Motivation
Instruction
Teacher
Interaction
Motivation
Metacognition
Learning
THRUSTS
Cognitive Factors
Metacognition &
Motivation
Social Communication
Comp Modeling &
Data Mining
Expert
Knowledge
Knowledge:
Deep,
conceptual,
fluent
Metacognition
Motivation
55
Thrust Research Questions
• Cognitive Factors. How do instructional events affect
learning activities and thus the outcomes of learning?
• Metacognition & Motivation. How do activities
initiated by the learner affect engagement with targeted
content?
• Social Communication. How do interactions between
learners and teachers and computer tutors affect
learning?
• Computational Modeling & Data Mining. Which
models are valid across which content domains, student
populations, and learning settings?
56
4th Measure of Robust
Learning
• Existing robust learning measures
– Transfer
– Long-term retention
– Acceleration of future learning
• New measure:
– Desire for future learning
• Is student engaged in subject?
• Do they chose to pursue further math, science, or
language?
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END
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