The transformer architecture, introduced in the groundbreaking "Attention Is All You Need" paper, revolutionized natural language processing. Unlike recurrent neural networks that process text sequentially, transformers use self-attention mechanisms to analyze entire input sequences simultaneously.
This attention mechanism allows the model to weigh the importance of different words when interpreting context. For instance, in the sentence "The bank was steep," the model learns to associate "bank" with a riverbank rather than a financial institution by analyzing surrounding words.
The training process involves two primary phases:
Pre-training: The model learns general language patterns by predicting masked words or next tokens in massive unlabeled datasets. This unsupervised learning creates a foundational understanding of language structure, semantics, and world knowledge.
Fine-tuning: Developers adapt pre-trained models for specific tasks using smaller, labeled datasets. This supervised learning refines the model's capabilities for applications like sentiment analysis, text classification, question answering, or code generation.
Modern LLMs employ autoregressive decoding, generating text one token at a time based on probability distributions. Temperature settings and sampling strategies control randomness versus determinism in outputs, allowing users to balance creativity with consistency.