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The Neural Data Router: Adaptive Control Flow in Transformers Improves Systematic Generalization

14 Oct 2021arXiv:2110.07732archive 2025-07-28

Róbert Csordás, Kazuki Irie, Jürgen Schmidhuber

Despite progress across a broad range of applications, Transformers have limited success in systematic generalization. The situation is especially frustrating in the case of algorithmic tasks, where they often fail to find intuitive solutions that route relevant information to the right node/operation at the right time in the grid represented by Transformer columns. To facilitate the learning of useful control flow, we propose two modifications to the Transformer architecture, copy gate and geometric attention. Our novel Neural Data Router (NDR) achieves 100% length generalization accuracy on the classic compositional table lookup task, as well as near-perfect accuracy on the simple arithmetic task and a new variant of ListOps testing for generalization across computational depths. NDR's attention and gating patterns tend to be interpretable as an intuitive form of neural routing. Our code is public.

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AttentionMask robertcsordas/ndr/layers/transformer/ndr.py official repository ran · metamorphic tier: deterministic MIT (permissive) · 28c21d66cc3361af · report
LayerWithVisualization robertcsordas/ndr/layers/transformer/ndr.py official repository ran · metamorphic tier: deterministic MIT (permissive) · e0c7a1fa7f8f1165 · report
MultiHeadAttentionBase robertcsordas/ndr/layers/transformer/ndr.py official repository ran · metamorphic tier: deterministic MIT (permissive) · 51c7e36152503851 · report
RegularizedLayer robertcsordas/ndr/layers/transformer/ndr.py official repository ran MIT (permissive) · c9270f7c12e670a5 · report
RelativeAttentionBase robertcsordas/ndr/layers/transformer/ndr.py official repository ran · metamorphic tier: deterministic MIT (permissive) · 5cc9456646f6915c · report
UniversalTransformerRandomLayerEncoderWithLayer RobertCsordas/ndr/layers/transformer/ndr.py official repository ran · our draft was wrong MIT (permissive) · 06cf617792cacde6 · report
shift robertcsordas/ndr/layers/transformer/ndr.py official repository ran · violated contract MIT (permissive) · fd07c4fcaa87fe04 · report
AttentionMergeMixin robertcsordas/ndr/layers/transformer/ndr.py official repository unverified MIT (permissive) · df234de93fadef4e · report
FixedRelativeMultiheadAttention robertcsordas/ndr/layers/transformer/ndr.py official repository unverified MIT (permissive) · fc0009775b8227c6 · report
FixedRelativeMultiheadAttentionBase robertcsordas/ndr/layers/transformer/ndr.py official repository unverified MIT (permissive) · 1a1e99543d24b2e2 · report
NDRResidual robertcsordas/ndr/layers/transformer/ndr.py official repository unverified MIT (permissive) · ac16130612e4864a · report

Tasks

ListOpsSystematic Generalization

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Methods

Absolute Position EncodingsAdamAttentionBPEDense ConnectionsDropoutLabel SmoothingLayer NormalizationLinear LayerMulti-Head AttentionPosition-Wise Feed-Forward LayerResidual ConnectionSoftmaxTransformer

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