Build latest book artifacts / build (push) Canceled after 0s
dependency resolution / resolve (3.11) (push) Canceled after 0s
dependency resolution / resolve (3.13) (push) Canceled after 0s
deploy-pages / build (push) Canceled after 0s
deploy-pages / deploy (push) Canceled after 0s
i18n consistency check / check (push) Canceled after 0s
provider adoption tests / test (chapter2/context-compression) (push) Canceled after 0s
provider adoption tests / test (chapter2/prompt-injection) (push) Canceled after 0s
provider adoption tests / test (chapter2/system-hint) (push) Canceled after 0s
provider adoption tests / test (chapter3/log-sanitization) (push) Canceled after 0s
web-search-agent tests / test (push) Canceled after 0s
web-search-agent tests / agentbook (push) Canceled after 0s
5.0 KiB
5.0 KiB
theme, title, author, date
| theme | title | author | date |
|---|---|---|---|
| default | Attention Is All You Need | Ashish Vaswani et al. | NIPS 2017 |
Attention Is All You Need
Authors: Ashish Vaswani et al.
Conference: NIPS 2017
Abstract
Key Innovation
- First sequence transduction model based solely on attention
- Dispenses with recurrence and convolutions entirely
- More parallelizable with significantly less training time
Performance Highlights
- WMT 2014 EN-DE: 28.4 BLEU (+2+ over previous SOTA)
- WMT 2014 EN-FR: 41.8 BLEU (new single-model SOTA)
- Trained in 3.5 days on 8 GPUs (small fraction of previous costs)
Background & Key Idea
Traditional Sequence Models
- Recurrent (LSTM/GRU): Sequential computation limits parallelization
- Convolutional: Requires multiple layers for long-range dependencies
The Transformer
- Replaces recurrence/convolution with self-attention
- Enables direct modeling of long-range dependencies
- Massive parallelization → faster training
Transformer Architecture
Encoder (left) and Decoder (right) with self-attention and feed-forward layers
Encoder & Decoder Stacks
Encoder (6 identical layers)
- Sub-layer 1: Multi-head self-attention
- Sub-layer 2: Position-wise feed-forward network
- Residual connections + layer normalization
- Output dimension:
d_model = 512
Decoder (6 identical layers)
- Sub-layer 1: Masked multi-head self-attention (prevents leftward flow)
- Sub-layer 2: Multi-head attention over encoder output
- Sub-layer 3: Position-wise feed-forward network
- Same residual connections and normalization
Attention Mechanism
Scaled Dot-Product Attention
\text{Attention}(Q, K, V) = \text{softmax}\left(\frac{QK^T}{\sqrt{d_k}}\right)V
- Scaling by
\sqrt{d_k}prevents small gradients - Efficient with matrix multiplication
Multi-Head Attention
\text{MultiHead}(Q, K, V) = \text{Concat}(\text{head}_1,...,\text{head}_h)W^O
h=8parallel heads,d_k=d_v=64- Captures diverse dependency patterns
Attention Applications
- Encoder-decoder attention: Queries from decoder, keys/values from encoder
- Encoder self-attention: All positions attend to all input positions
- Decoder self-attention: Positions attend to previous positions (masked)
Positional Encoding
Adds sequence position information via sinusoidal functions:
\text{PE}_{(pos,2i)}=\sin(pos/10000^{2i/d_{\text{model}}})
\text{PE}_{(pos,2i+1)}=\cos(pos/10000^{2i/d_{\text{model}}})
- Same dimension as embeddings (
d_{\text{model}}) - Enables learning of relative positions
- Performs similarly to learned embeddings
Why Self-Attention?
| Layer Type | Complexity | Sequential Ops | Max Path Length |
|---|---|---|---|
| Self-Attention | O(n^2 \cdot d) |
O(1) |
O(1) |
| Recurrent | O(n \cdot d^2) |
O(n) |
O(n) |
| Convolutional | O(k \cdot n \cdot d^2) |
O(1) |
O(\log_k n) |
- Better parallelization than RNNs
- Shorter path length than CNNs
- More interpretable attention patterns
Training Setup
Data & Batching
- WMT 2014 EN-DE (4.5M pairs), EN-FR (36M pairs)
- Byte-pair encoding (37K/32K vocab)
- Batches with ~25K source/target tokens
Hardware & Schedule
- 8 NVIDIA P100 GPUs
- Base model: 100K steps (12h), Big model: 300K steps (3.5d)
Optimization
- Adam (
\beta_1=0.9,\beta_2=0.98), learning rate warmup - Dropout (0.1), label smoothing (0.1)
Machine Translation Results
| Model | EN-DE BLEU | EN-FR BLEU | Training Cost (FLOPs) |
|---|---|---|---|
| GNMT + RL Ensemble | 26.30 | 41.16 | 1.8 \cdot 10^{20} |
| ConvS2S Ensemble | 26.36 | 41.29 | 7.7 \cdot 10^{19} |
| Transformer (big) | 28.4 | 41.8 | $2.3 \cdot 10^{19}$ |
- Outperforms all previous SOTA with lower training cost
Attention Visualization: Long-Distance Dependencies
Encoder self-attention (layer 5) tracking "making...more difficult" dependency
Attention Visualization: Anaphora Resolution
Attention heads resolving "its" to "The Law"
Conclusion & Future Work
Key Contributions
- Introduced Transformer, first attention-only transduction model
- Eliminated recurrence/convolution → better parallelization
- Set new SOTA in machine translation with lower training cost
- Generalizes to other tasks (e.g., constituency parsing)
Future Work
- Apply to other modalities (images, audio)
- Explore local attention for large sequences
- Improve generation sequentiality
- Enhance attention interpretability