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Interpretation methods

Choose an interpretation method based on the model interface, explanation you need, and available compute. The toolkit covers local interpretation methods for time-series models across perturbation, gradient, distributional, learned-mask, and surrogate approaches. They follow the familiar .attribute(...) pattern from Captum and Time Interpret.

WinTSR attribution heatmap recovering a planted ground-truth signal at feature 0, steps 20-25, on a synthetic AR(1) series

A synthetic series with a known answer — one feature, one window, everything else noise. WinTSR's saliency map (right two panels) lights up exactly where the ground truth (left) says it should. Reproduce this with the quickstart notebook.

At a glance

Following Captum's algorithm comparison matrix, here is what each method needs from your model and how it's computed:

Method Type Model requirement Requires baseline Paper API doc
WinTSR Perturbation Any callable Yes Islam & Fox, arXiv:2412.04532 reference/wintsr.md
TSR Gradient Differentiable Yes Ismail et al., NeurIPS 2020 reference/tsr.md
WinIT Perturbation Any callable No (generative) Leung et al., ICLR 2023 reference/winit.md
GateMask Learned mask Any callable No (learned) Liu et al., ICLR 2024 reference/gate_mask.md
Occlusion Perturbation Any callable Yes Zeiler & Fergus, ECCV 2014 captum.ai/api/occlusion.html
Feature Ablation Perturbation Any callable Yes Kokhlikyan et al., arXiv:2009.07896 captum.ai/api/feature_ablation.html
Feature Permutation Perturbation Any callable No (permuted batch) Kokhlikyan et al., arXiv:2009.07896 captum.ai/api/feature_permutation.html
Augmented Occlusion Perturbation Any callable No (bootstrapped) Enguehard, ICML 2023 tint: attr.AugmentedOcclusion
Integrated Gradients Gradient Differentiable Yes Sundararajan et al., ICML 2017 captum.ai/api/integrated_gradients.html
Gradient SHAP Gradient Differentiable Yes (distribution) Lundberg & Lee, NeurIPS 2017 captum.ai/api/gradient_shap.html
FIT Perturbation Any callable (classification only) No (generative) Tonekaboni et al., NeurIPS 2020 tint: attr.Fit
Dyna Mask Learned mask Any callable No (learned) Crabbé & van der Schaar, ICML 2021 tint: attr.DynaMask
Extremal Mask Learned mask Any callable No (learned) Enguehard, ICML 2023 tint: attr.ExtremalMask
Lime Surrogate Any callable Yes Ribeiro et al., KDD 2016 captum.ai/api/lime.html

Looking for which model architectures each of these has actually been run against? See Supported models.

Occlusion-based

WinTSR — Two-stage attribution. Stage one scores each time step by occluding it entirely (a time-relevance score). Stage two scores each feature within a time step, but only for the time steps that clear a relevance threshold from stage one, using a sliding window that respects the dependency between neighbouring steps. The two scores multiply to give the final attribution. Prior approaches either ignore the dependency between consecutive time steps, or score time and features independently and combine them after the fact; WinTSR does both jointly, and skips low-relevance time steps in stage two so it stays fast on long sequences.

End-to-end walkthrough: train DLinear on real ETTh1 data and derive a when-and-where forecasting insight.

Occlusion — Slides a window over the input, zeroing (or replacing) each region in turn and measuring the change in output. The base operation WinTSR's stage one builds on.

Feature Ablation — Occludes one feature (or a user-defined group of features) at a time across the whole sequence, rather than a sliding window.

Feature Permutation — Same idea as ablation, but shuffles a feature's values across the batch instead of zeroing it, so the replacement stays in-distribution.

Augmented Occlusion — Occlusion with a learned, data-driven baseline (sampled from a bootstrapped distribution) instead of a fixed zero or mean baseline.

Gradient-based

TSR — The method WinTSR generalizes. Also two-stage (time relevance, then feature relevance), but computes both stages with Integrated Gradients rather than occlusion, and does not account for temporal dependency between time steps within a stage. Needs a differentiable model — no black-box support.

Integrated Gradients — Accumulates gradients along a straight-line path from a baseline to the input, giving an attribution that satisfies completeness and sensitivity axioms.

Gradient SHAP — Approximates Shapley values by averaging Integrated-Gradients-style paths from multiple noisy baselines.

Delayed / distributional importance

WinIT — Computes delayed feature importance: how much a feature's past values (within a sliding window) still influence the current prediction, using a distributional distance (Jensen-Shannon or prediction-difference) between the real and counterfactual forecast. Unlike WinTSR, it does not separate a time-relevance and a feature-relevance stage. Its delay concept is built into the progressive backward masking and distributional-distance score; the returned attribution has shape (batch, n_output, seq_len, n_features), with no separate delay axis.

Walkthrough: compare WinIT and WinTSR on the same synthetic task.

FIT — Scores each observation by the KL-divergence between the predictive distribution with and without it. Classification only.

Learned masks

GateMask — The gating mechanism from ContraLSP: trains a small network per input to produce sparse, binary-skewed gates over (time, feature), using counterfactual perturbations and contrastive learning to keep the masked input's distribution close to the original. Requires fitting a mask network per batch (via a pytorch_lightning.Trainer), so it is markedly slower than occlusion- or gradient-based methods.

Walkthrough: learn a GateMask and compare 10, 50, and 150 training epochs.

Dyna Mask — Learns a per-timestep mask with a smoothness/sparsity penalty, trained to preserve the model's prediction under the masked input.

Extremal Mask — Learns masks that push predictions towards a target extremum (rather than just preserving the original prediction), trained jointly with the perturbation applied under the mask.

Surrogate

Lime — Fits a local, interpretable surrogate model (typically linear) around the input to approximate the black-box model's behaviour in that neighbourhood.

Choosing a method

  • Default: WinTSR. It's the method this package exists for, and the paper's results show it best recovers ground-truth relevance in both time and feature dimensions.
  • Need a differentiable, gradient-only method: TSR, Integrated Gradients, or Gradient SHAP.
  • Classification model, want instance-wise delayed importance: WinIT or FIT.
  • Want a learned, sparse binary mask rather than a continuous score: GateMask, Dyna Mask, or Extremal Mask.
  • Want a quick, model-agnostic baseline with no training step: Occlusion, Feature Ablation, Feature Permutation, or Augmented Occlusion.