LLM’s: Roles

Author

Robert W. Walker

Published

April 12, 2026

Outline

  1. A Basic Review of Our Tool.
  2. The Input: a role.
    • Anatomy of both.
    • Thinking models and the like.
  3. The reading on personas.

Aside: RAGs and tool availability for local models. Conversations with qwen details how far local models can go just with search.

Architectural Summary

qwen what are you?

Summary of Gemini 3 Flash Specs

Hyperparameter Specification
Model Type Sparse Mixture-of-Experts (MoE)
Vocabulary Size 256,000 tokens
Context Window Up to 1,000,000 tokens
Distillation Optimized from larger Gemini 3 variants

Key Takeaway: My performance is the result of distillation, where I am trained to mimic the logic of larger models while maintaining a lean “active” parameter count.

Some Disquieting News

Mythos

The Big Picture

LLMs are varyingly capable repositories of information that is rendered as output by a model with what that entails from before the core input: prompts. How do we articulate our mental goal to the model?

BUT, those prompts come from a role context.

Role Prompting & Persona Framing

Why Role Prompting Works

Assigning a role activates domain-specific token patterns embedded during training. “You are a senior cardiologist” and “You are a creative writing professor” produce meaningfully different outputs — even for identical task instructions.

Prompting Best Practices

  • Be specific: "You are a senior backend engineer specializing in distributed systems" outperforms "You are a programmer"
  • Align role to audience: pair a CFO role with an instruction to write for "a board of directors unfamiliar with technical debt"
  • Use role to set limits: "You are a helpful assistant that never speculates beyond the provided data"

System Prompt vs. User Prompt

Layer Best for
System prompt Persistent persona, behavioral constraints, output schema, safety rails
User prompt Task-specific instructions, dynamic context, examples

Separate concerns cleanly. Don’t repeat system-level constraints in every user turn.

An Example in Two Parts

Compare this to this

qwen/qwen3.5-35b-a3b Thought for 3 minutes 59 seconds

qwen/qwen3.5-35b-a3b Thought for 2 minutes 2 seconds

Two Takes on the System

  • System roles from two perspectives:

Personas [from Nature]

We should view LLMs not as entities with their own beliefs or intentions, but as improvisational actors engaged in role-play.

Key Themes

  1. Moving Beyond Anthropomorphism: The authors argue that humans have a natural tendency to “anthropomorphize” AI—ascribing human-like qualities like consciousness, intent, or self-awareness to them. This often leads to a misunderstanding of how these models actually function.
  2. The “Role-Play” Framework: Instead of viewing an LLM as a single persona, the article suggests we see it as a “multiverse generator.” Based on the prompt provided, the model “casts” itself into a specific role and generates text that would be likely for that character in that specific context.
  3. Deception vs. Apparent Deception: Under this framework, if an LLM provides false information, it isn’t “lying” in the human sense (which requires a conscious intent to deceive). Rather, it is playing a role—such as a “helpful assistant” or a “hallucinating narrator”—where providing that specific text is the statistically likely next step in the script.
  4. Self-Awareness: Similarly, when a model claims to be “frightened” or “alive,” the authors argue it isn’t experiencing those feelings. It is simply performing the role of a character that expresses those sentiments, often because its training data is full of human sci-fi tropes and philosophical discussions about AI consciousness.
  5. The “Superposition” of Personas: The model exists in a state where it can take on any number of characters. The prompt and the ongoing conversation act as a “collapse” of these possibilities into a single, temporary role.

Why it matters?

This perspective is important for both developers and the public. By treating LLM behavior as role-play rather than genuine agency, we can more accurately predict their failures (like hallucinations) and design better safety guardrails without being distracted by the “illusion” of a human-like mind behind the screen.

A Commercial Use of Personas

An example company

A chat

A Use of Personas

A Conversation with Claude