August 12th, 2024

Transformer Explainer

The Transformer architecture has transformed AI in text generation, utilizing self-attention and key components like embedding and Transformer blocks, while advanced features enhance performance and stability.

Read original articleLink Icon
Transformer Explainer

The Transformer architecture, introduced in the 2017 paper "Attention is All You Need," has revolutionized artificial intelligence, particularly in deep learning models for text generation, such as OpenAI's GPT, Meta's Llama, and Google's Gemini. Transformers utilize a self-attention mechanism that enables them to process entire sequences and capture long-range dependencies effectively. The architecture consists of three main components: embedding, Transformer blocks, and output probabilities. The embedding process converts text into numerical vectors, while Transformer blocks include multi-head self-attention and a Multi-Layer Perceptron (MLP) layer, which refine token representations. The self-attention mechanism computes attention scores to determine the relevance of tokens, while masked self-attention prevents the model from accessing future tokens during prediction. The final output is generated by projecting processed embeddings into a probability distribution over the vocabulary, allowing the model to predict the next token. Advanced features like layer normalization, dropout, and residual connections enhance training stability and performance. The Transformer Explainer tool allows users to interactively explore these concepts, input text, and adjust parameters like temperature to see how they affect model predictions. This interactive approach aids in understanding the inner workings of Transformer models.

- The Transformer architecture has transformed AI, especially in text generation.

- Key components include embedding, Transformer blocks, and output probabilities.

- Self-attention allows the model to capture relationships between tokens effectively.

- Advanced features like layer normalization and dropout improve model performance.

- The Transformer Explainer tool provides an interactive way to learn about Transformers.

Link Icon 4 comments
By @jebarker - 8 months
I love this visualization, but when it generates tokens with temperature=1 it seems to be picking the second highest logit/probability, not the highest. Is that a mistake or am I missing something?
By @mannykannot - 8 months
The article uses the phrase 'semantic meaning' three times, but we are dealing with tokens here, which leads me to wonder what sort of semantics sub-word tokens have. For example, does compositionality [1] apply over sub-word tokens? Does the success of LLMs in generating text that could pass as human-generated suggest that it does?

[1] https://en.wikipedia.org/wiki/Principle_of_compositionality

By @LZ_Khan - 8 months
Question: what is the purpose of softmax for words/tokens before the final word? Isn't it only the softmax distribution respective to the final word that gets used for the next token prediction? That was my understanding at least.