Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse...

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G I C SDM ’17 Michael T. Lash 1 , Qihang Lin 2 , W. Nick Street 2 , Jennifer G. Robinson 3 , and Jeffrey Ohlmann 2 1 Department of Computer Science, 2 Deparment of Management Sciences, 3 Department of Epidemiology www.michaeltlash.com

Transcript of Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse...

Page 1: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

GENERALIZED INVERSECLASSIFICATIONSDM ’17

Michael T. Lash1, Qihang Lin2, W. Nick Street2, JenniferG. Robinson3, and Jeffrey Ohlmann2

1Department of Computer Science, 2Deparment of ManagementSciences, 3Department of Epidemiology

www.michaeltlash.com

Page 2: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

What is inverse classification?

# The process of making meaningful perturbations to a testinstance such that the probability of a desirable outcome ismaximized.

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Page 3: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

What is inverse classification?

# The process of making meaningful perturbations to a testinstance such that the probability of a desirable outcome ismaximized.

1

Page 4: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

What is inverse classification?

# The process of making meaningful perturbations to a testinstance such that the probability of a desirable outcome ismaximized.

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Page 5: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

What is inverse classification?

# The process of making meaningful perturbations to a testinstance such that the probability of a desirable outcome ismaximized.

1

Page 6: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

What is inverse classification?

# The process of making meaningful perturbations to a testinstance such that the probability of a desirable outcome ismaximized.

1

Page 7: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

What is inverse classification?

# The process of making meaningful perturbations to a testinstance such that the probability of a desirable outcome ismaximized.

1

Page 8: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

What is inverse classification?

# The process of making meaningful perturbations to a testinstance such that the probability of a desirable outcome ismaximized.

1

Page 9: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

What is inverse classification?

# The process of making meaningful perturbations to a testinstance such that the probability of a desirable outcome ismaximized.

What about the meaningful part of the definition?1

Page 10: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Meaningful Perturbations

Well...lets visit some past work!# Michael T. Lash, Qihang Lin, W. Nick Street, and

Jennifer G. Robinson, “A budget-constrained inverseclassification framework for smooth classifiers”, arXivpreprint arXiv:1605.09068, submitted.

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Page 11: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Meaningful Perturbations

Begin with a basic formulation.

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Page 12: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Meaningful Perturbations

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Page 13: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Meaningful Perturbations

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Page 14: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Meaningful Perturbations

Some regressor

Segment features.

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Page 15: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Meaningful Perturbations

Some regressor

Estimate indirectly changeable.

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Page 16: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Meaningful Perturbations

Some regressor

Update objective function. Add constraints.

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Page 17: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Meaningful Perturbations

Some regressor

Cost-change function

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Page 18: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Meaningful Perturbations

Some regressor

Budget

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Page 19: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Meaningful Perturbations

Some regressorBounds

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Page 20: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Main Contributions

1. Relax assumptions about f (·).

Some regressorBounds

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Page 21: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Main Contributions

1. Relax assumptions about f (·).

Some regressorBounds

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Page 22: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Main Contributions

1. Relax assumptions about f (·).

Some regressorBounds

Generalized inverse classification 3

Page 23: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Main Contributions

1. Relax assumptions about f (·).2. Quadratic cost-change function.

Some regressor

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Page 24: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Main Contributions

1. Relax assumptions about f (·).2. Quadratic cost-change function.

Some regressor

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Page 25: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Main Contributions

1. Relax assumptions about f (·).2. Quadratic cost-change function.

Some regressor

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Page 26: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Main Contributions

1. Relax assumptions about f (·).2. Quadratic cost-change function.3. Three real-valued heuristic optimization

methods and two sensitivity analysis-basedoptimization methods.

* Projection operator to maintain feasibility.

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Page 27: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Optimization Methodology

Heuristic

# Hill Climbing + Local Search (HC+LS)# Genetic Algorithm (GA)# Genetic Algorithm + Local Search (GA+LS)

Sensitivity Analysis

# Local Variable Perturbation – First Improvement (LVP-FI)# Local Variable Perturbation – Best Improvement (LVP-BI)

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Page 28: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Experiment Decisions and Data

# f (·): Random forest# H(·): Kernel regression# Dataset 1: Student Performance (UCI Machine Learning

Repository).# Dataset 2: ARIC# One f for optimization, separate f for heldout evaluation.

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Page 29: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Results: Student Performance

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Page 30: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Results: Student Performance

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Page 31: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Results: ARIC

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Page 32: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Results: ARIC

Need sparsity constraints 9

Page 33: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Conclusions

# Generalized Inverse Classification: can use virtually anylearned f (as shown by experiments w/ Random Forestclassifier).

# Our proposed methods were successful, although thisvaried by dataset.

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Page 34: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

GENERALIZED INVERSECLASSIFICATIONSDM ’17

Michael T. Lash1, Qihang Lin2, W. Nick Street2, JenniferG. Robinson3, and Jeffrey Ohlmann2

1Department of Computer Science, 2Deparment of ManagementSciences, 3Department of Epidemiology

www.michaeltlash.com

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Page 35: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Causality and Inverse Classification

# Yes! ....# What we’re doing:

1. Imposing our own causal structure (DAG).2. We’re not taking the usual counterfactual approach.

# Future work will focus on incorporating causalmethodology...

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Page 36: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Causality and Inverse Classification

# Yes! ....

# What we’re doing:1. Imposing our own causal structure (DAG).2. We’re not taking the usual counterfactual approach.

# Future work will focus on incorporating causalmethodology...

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Page 37: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Causality and Inverse Classification

# Yes! ....# What we’re doing:

1. Imposing our own causal structure (DAG).2. We’re not taking the usual counterfactual approach.

# Future work will focus on incorporating causalmethodology...

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Page 38: Generalized Inverse Classificationmichaeltlash.com/slides/lash_sdm2017_slides.pdfGeneralized Inverse Classification SDM’17 Michael T. Lash1,QihangLin2,W.NickStreet2,Jennifer G.Robinson3,andJeffreyOhlmann2

Causality and Inverse Classification

# Yes! ....# What we’re doing:

1. Imposing our own causal structure (DAG).2. We’re not taking the usual counterfactual approach.

# Future work will focus on incorporating causalmethodology...

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