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Did dropping recurrence throw away a useful inductive bias?

LElenaf· ETH Zürich· about 2 months ago

Transformers replaced recurrence/convolution with pure attention + positional encodings. RNNs/CNNs bake in locality and sequential order; attention has to learn them from data. Is the lesson 'inductive biases don't matter at scale', or did we just relocate the bias into positional encodings and pretraining?

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TBtbeckerabout 2 months ago

I'd say we traded a strong fixed bias for a weak learnable one — and that only pays off at scale. On small datasets, convolutional/recurrent biases still win; plenty of low-data benchmarks where Transformers underperform without heavy pretraining.

LElenafabout 2 months ago

Fair, but 'at scale' is doing a lot of work — almost every deployed model now is at that scale. So practically the bias-free bet won, even if it isn't universally true.

MIminseokabout 2 months ago

저는 위치 인코딩이 사실상 순서 편향을 다시 넣은 거라고 봐요. 진짜 '편향 없음'이 아니라 어떤 편향을 줄지를 데이터/설계로 옮긴 거죠. RoPE 같은 상대 위치 인코딩이 잘 되는 게 그 증거 같습니다.

TBtbeckerabout 2 months ago

Agreed — RoPE/ALiBi succeeding is evidence the order bias is still essential; we just made it softer and tunable. What we genuinely dropped is hard locality, which attention re-learns as a soft version (induction heads, local patterns).

AMamir_rabout 2 months ago

A middle position: attention is a more flexible prior, not the absence of one. 'Any token may attend to any token, weighted by content' is still a strong assumption — just a different one than locality.

YUyukisabout 1 month ago

Late to this, but a near-controlled experiment: vision Transformers needed huge data (JFT-300M) to beat CNNs, then ViT + strong augmentation closed the gap on ImageNet alone. That's almost a clean demonstration that the inductive bias matters exactly when data is limited.

MIminseokabout 1 month ago

@yukis 좋은 예시네요. 결국 'scale이 편향을 대체한다'가 아니라 'scale이 있으면 편향 없이도 버틴다'가 더 정확한 표현 같아요.