---
title: The three levers — AI basics, lesson 2
description: A generic model becomes yours in three places: its weights, through training; what it looks up at question time; and what it is told at the start of a session.
url: https://instibrain.ai/guides/ai-basics/the-three-levers
updated: 2026-11-07
site: https://instibrain.ai/llms.txt
---

lesson 2 of 8 · ai basics

# The three levers.

A generic model becomes yours in three places: its weights, what it looks up at question time, and what it is told at the start.

## new words

**Weights**
The numbers inside the model, billions of them. Training sets them, and nothing else changes them.

**Training**
Changing the weights with examples. Pretraining builds the model from nothing; fine-tuning adjusts a finished one with your examples.

**Retrieval**
Finding the right paragraph at question time and putting it into the prompt. Lessons 3 to 7 take it apart.

**Context**
Everything the model is given before and in your message: instructions, pages, the results of a lookup. Claude basics, lesson 2.

## the lesson

Every company uses the same models. What makes one AI yours is where you put what it must know and how it must act. There are three places: the weights, set by training; the paragraphs fetched into the prompt; and the pages and instructions it reads first.

| Lever | Facts | Behaviour | Fresh |
| Weights | Poor, with no source | Yes | Stale from the day training ends |
| Retrieval | Cited: the answer names its chunk | No | After the next reindex |
| Context | Whole, in the window | By instruction | On save |

Facts go in context or retrieval. A way of answering goes in an instruction file, which costs nothing to change, or in a fine-tune. Judgment is the lab's job: pick a better model.

Fine-tuning fails three tests: fresh, cited and private. Context passes all three when the store is yours. instibrain is the third lever: your pages are read at the start of every session, and the folder you start in decides which ones.

Three places to change a generic model. Your pages are the third.

## try it

Type this and press Enter:

```
What do you know about my company? For each fact, say where it came from: your training, a page you read at the start, or a lookup you made just now.
```

## you should see

- Every fact names a page or a lookup. Nothing about your company came from training.
- If Claude read nothing yet, it says so and offers to read your spaces.

---

instibrain is made by WebWork AI, Inc. Everyone uses the same models · the difference is what yours knows.