Student Data (Contd..)
• How much does the student know?
• Ask the student!
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Knowledge Tracing (KT)
• For some skill K
• Given student’s response sequence 1 to n, predict n+1
0 0 0 1
1 1 ?
1 ………..……… n n+1
Chronological response sequence for student Y
[ 0 = Incorrect response 1 = Correct response]
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How do we approach this?
• Modelling learner’s knowledge acquisition process
• Fairly complex
• Need a
• General model
• Flexible model
• Powerful model
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Play the best card: Deep Learning
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Deep Knowledge Tracing (DKT)
• Recurrent Neural Networks (RNNs)
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Deep Knowledge Tracing (DKT)
• RNN or LSTM Model
0.9,0.3,0.2 0.8,0.2,0.1 0.8,0.5,0.3
Q1 Q2 Q3
….
Skill A Skill B Skill C
1.0,0.3,0.7
pCorrect(Skill A), pCorrect(Skill B), pCorrect(Skill C)
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Inter-skill Relationships
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Dataset
• 6th Grade Math CBSE Curriculum
• 22 topics, 69 sub-topics, 119 sub-sub-topics
• 442 skills (LGs), 1523 problems
• 7780 students, 176 schools
• 2.4 million problem attempts
• 5.6 million data-points
• 76% avoidances (positive class:1)
BKT: Parameters
• BKT: 2-state Hidden Markov Model (HMM)
• P(L0
): Probability of Initial Knowledge
• P(T): Probability of Learning
• P(S): Probability of Slip
• P(G): Probability of Guess
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Shallow* Vs Deep
Shallow* Deep
Shallow* = Deep
Performance
Parameters
4 x # skills
pInit, pLearn, pGuess, pSlip
Few hundred thousand
parameters
Interpretability
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Deep Model: Advantages
• Intelligent Curriculum Design
• Finding best sequence of tasks
• Discovery of structure
• Instead of skill labels, question labels can be used as input
• Complex representations and features
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is Deep Learning
really
DEEP?
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References
• Knowledge Tracing: Modelling the acquisition of
procedural knowledge (Corbett et. Al., 1995)
• Bloom’s Two Sigma Problem (1984)
• Deep Knowledge Tracing (Peich et. Al., 2015)
• How deep is Knowledge Tracing? (Khajah et. Al., 2016)
• Few hundred parameters outperform few hundred
thousand? (Lalwani et. Al.), 2017