source: https://bradleyboehmke.github.io/HOML/iml.html
Assumptions:
- Every model is linear on a local scale;
- It is possible to fit a simple surrogate model around a single observation that will mimic how the global model behaves at the locality;
Algorithm:
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Permute training data to create replicated feature data with slight value modifications;
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Compute proximity measure (1 - distance) between observation of interest and each of the permuted observations;
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Apply selected machine learning model to predict outcomes of permuted data;
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Select m number of features to best describe predicted outcomes; (Forward selection, ridge or lasso regression, decision tree)
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Fit a sample model to the permuted data, explaining the complex model outcome with m features from the permuted data weighted by its similarity to the original observation;
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Use the resulting feature weights to explain local behaviour;
Explaining indiividual predictions by borrowing ideas from coalitional game theory, Shapley Values.
Partial dependence algorithm with added step-wise procedure.