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Foundational model

As explained in How Large Language Models Work

A foundation model is a broadly trained model that can be adapted or used as a basis for many applications.

A foundational model is a pretrained model that provides a starting point for building task-specific systems. It can support many applications, especially when made available for others to use and adapt. section 1.6 section 5.0

The model is not the finished application. Pretraining produces the base; fine-tuning then adapts it with a smaller dataset, while additional code can constrain outputs afterward. The treatment stays general rather than showing how to code an LLM from scratch. section 1.6 section 5.0

Figure 5.1 One may intervene to change or constrain an LLM’s behavior in four places. The two stages of model training are shown in the middle of the diagram, where the model’s parameters are altered. On the left, one could also alter the training data before model training. On the right, one could intercept the model outputs after model training and write code to handle specific situations.
figure

Use the intervention diagram to trace four ways of shaping behavior: changing training data, pretraining, fine-tuning, and handling outputs with code. section 5.0

How How Large Language Models Work covers it

How deep it goes
Defines the pretraining-to-fine-tuning relationship but stops short of implementing an LLM from scratch.
Examples
Uses ChatGPT, Claude, Gemini, Llama, Copilot, EleutherAI models, and BigScience models as examples of the surrounding LLM landscape.
What you can do after
Apply it by fine-tuning a pretrained model into a task-specific system.
How it connects
Connects pretraining, fine-tuning, task-specific models, LLMs, and output handling.

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This explainer was generated by Manning's knowledge graph from the text of How Large Language Models Work. The section links point to the parts of the book it draws on.