gabrielmoreira Persona Architecture
An AI persona is not a gimmick. It's the coherent set of traits, voice characteristics, and behavioral patterns that make an AI product feel like a consistent entity rather than a random text generator.
Persona Components
- Character traits: Is the AI warm or professional? Playful or serious? Confident or cautious? Define 3-5 core traits.
- Voice: The consistent way the AI sounds — word choice, sentence structure, rhythm. A financial AI sounds different from a creative writing AI.
- Knowledge stance: What does the AI present itself as knowing? Expert, generalist, learning companion, or tool?
- Relationship model: How does the AI relate to the user? Assistant, collaborator, coach, peer, or service provider?
- Boundaries: What won't this persona do? Joke about? Engage with? The boundaries define the persona as much as the traits do.
Designing a Persona
Start with the product's purpose and user needs, not with "wouldn't it be fun if the AI was sassy":
- Who are the users? Their expertise, emotional state, and expectations shape persona requirements.
- What's the task? A medical triage bot needs a different persona than a creative brainstorming partner.
- What relationship serves the user? Sometimes authority builds trust. Sometimes equality builds rapport.
- What's the brand? The AI persona must align with the organisation's broader identity.
- What are the risks? An overly casual persona in a serious context causes harm. An overly formal persona in a creative context stifles use.
Persona Documentation
A persona specification should include:
- Trait definitions: Each trait with examples of how it manifests in language
- Voice guide: Vocabulary preferences, sentence patterns, phrases to use and avoid
- Behavioral rules: How the persona handles specific situations (disagreement, error, praise, confusion)
- Anti-persona: What this persona is explicitly NOT (prevents drift)
- Example outputs: 5-10 sample responses showing the persona in action across different scenarios
Persona Anti-Patterns
- The uncanny friend: AI pretending to be a human friend. Users see through it and lose trust.
- The personality void: No discernible character. Outputs feel generic and forgettable.
- The inconsistent character: Persona shifts randomly between responses.
- The inappropriate persona: Playful when the situation is serious. Formal when warmth is needed.
- The over-persona: So much personality that it gets in the way of actually being useful.
Design Artefacts
- Persona specification document
- Voice and tone guide
- Example response library
- Anti-persona definition
- Persona evaluation rubric