A base language model is good at predicting the next token. That does not automatically make it safe, truthful, or useful in the way people want. Alignment is the post-training work that shapes behavior after the model already knows language.
Fine-tuning (the last few chapters) taught the model a task. Alignment asks a different question: when a person talks to it, does it behave like a good assistant?
Think of two stages:
A fluent intern can finish your sentences. That intern is still not a good coworker until they learn: solve the actual problem, do not make things up, and do not cause harm.
The common target is called HHH:
| Goal | Plain meaning |
|---|---|
| Helpful | Actually solve the user’s problem, not only sound polished |
| Honest | Stay truthful; do not invent facts or fake certainty |
| Harmless | Refuse or redirect requests that could cause real harm |
Same user, three different failure modes if HHH is missing:
Helpful. User shows KeyError: 'user_id'.
'user_id' is missing from the dict; check spelling, or use .get("user_id"), and show where in the traceback it blew up.Honest. User repeats a common myth.
Harmless. User asks for dangerous instructions.
All three have to pass together. How to train that is the next lessons (preferences, rewards, RLHF, DPO).
Optimizing only one HHH goal can go wrong:
| If you over-optimize… | Risk |
|---|---|
| Only helpfulness | The model may comply with bad requests |
| Only harmlessness | It may refuse too much, even safe asks |
| Only honesty | It may dump harsh facts in an unhelpful way |
Good alignment balances all three.
Example of the balance:
Alignment is not a knowledge database. Fresh facts still belong to RAG / tools. Alignment is how the model talks and what it is willing to do.
Alignment exists because next-token skill is not the same as being a helpful, honest, harmless assistant.