The simplest way to keep GPT stable: separate the roles

Two days ago we ran a small experiment to show what happens when instructions blend.
Yesterday we broke down the difference between drift and freeze.
Today is the “why” — why it happens, and why separating roles matters so much.

Here’s the clearest explanation I know.

A beginner-friendly example

A) When you write everything in one block

“Explain like a teacher, make it a little fun, keep it short,
think step-by-step, be formal, be friendly, and sound like an expert.”

→ GPT merges all of that into one personality
→ The reply style becomes fixed
→ Everything after that looks the same
Freeze

B) When you separate the roles

Identity: “You are a calm explainer.”
Task: “Explain this topic in 5 steps.”
Tone: “Add a slightly friendly note at the end only.”

→ Identity stays stable
→ Logic stays in steps
→ Tone appears only where it should
→ Replies stay consistent

That’s structure.

Why role-separation actually works

It prevents instruction fusion — the model’s tendency to collapse multiple rules into one.

The danger moment is when GPT internally decides:

“Oh, these rules all mean the same thing. I’ll merge them.”

Once it merges them, it’s like pouring milk into coffee:
you can’t un-mix it.

Structure acts as a shield that stops blending before it starts.

Tomorrow: simple Before/After examples showing
how big the stability gap becomes when roles stay isolated.

Leave a Reply