Per token transformation which has parameter (not a perfect distribution)
BN normalizes the activations of each batch, while LN normalizes the activations of each layer. Usually with Residual Connection like below.
Normalizes the output of a layer to stabilize the training process and reduce differences in learning rates between layers
You only need to change one dimension from Batch Normalization. After the introduction of the Transformer Model, there haven't been many changes, but one of the biggest changes is that Layer Normalization in the Attention Mechanism block changed from Post-Norm to Pre-Norm
with linear transformation
To compensate for the fact that the normalization process can limit the model's expressive power
- - scale
- - shift
eps- epsilon is a small value added to the denominator during the normalization process to prevent division by zero
- element wise affine - learnable scaling and shifting operations applied to each element
Layer Normalizations
Experimental evidence shows that removing LayerNorm (LN) from GPT-2 models results in minimal performance loss. The research points out that LN introduces non-linearities that complicate mechanical interpretability (Linear Representation Hypothesis). Since removing LN all at once breaks the model, researchers gradually replaced it with FakeLN (fixed scale) layer by layer and path by path, with minimal fine-tuning. The removal of LN eliminated Conf-Neurons (Confidence Neurons), reducing model overconfidence (low entropy was observed). Additionally, the Attention Sink phenomenon, where the L2 norm of the first token becomes excessively large, was diminished

Seonglae Cho