Prototype Planning

Overview

Define what to build, at what fidelity, to learn what you need to know without over-investing.

When to Use

• Before starting any prototype
• When transitioning from Ideate to Prototype phase
• When deciding between low-fi and high-fi approaches
• When prototype scope is unclear

How to Apply

1. Define Learning Goals

What questions must this prototype answer?

Examples:

• "Will users understand the core concept?"
• "Can users complete the task with this flow?"
• "Is the information architecture clear?"
• "Will this perform fast enough?"
• "Do users want this feature?"

2. Choose Appropriate Fidelity

Match fidelity to learning goals:

Low Fidelity (paper sketches, wireframes, clickable mockups)

• Test concepts and flows
• Validate information architecture
• Early user reactions
• Fast iteration

Medium Fidelity (interactive prototypes, basic functionality)

• Test specific interactions
• Validate workflows end-to-end
• More realistic user testing
• Some technical validation

High Fidelity (working code, realistic data, edge cases)

• Performance testing
• Technical feasibility
• Real-world usage patterns
• Pre-launch validation

Rule: Use the lowest fidelity that answers your questions.

3. Define Scope

In scope:

• What features/flows are included?
• What data/content is needed?
• What interactions must work?

Out of scope:

• What can be faked or simulated?
• What can wait for later iterations?
• What's not relevant to learning goals?

4. Plan Iteration

Success criteria: What would make this prototype worth pursuing? Failure criteria: What would invalidate this idea? Iteration plan: How will you test with users? Timeline: How long to build and test?

5. Document the Plan

Create in ideas/[idea-name]-001.md:

# Offline Capture - Prototype 001

**Fidelity**: Low (paper + clickable mockup)
**Timeline**: 3 days build, 1 week testing

## Learning Goals
1. Do users understand offline sync concept?
2. Is 3-field quick capture sufficient?
3. Will users trust data won't be lost?

## Scope
**In scope**:
- Quick capture form (3 fields)
- Offline indicator
- Sync status display

**Out of scope**:
- Full form (can fake)
- Conflict resolution (assume happy path)
- Settings/configuration

## Success Criteria
- 4/5 users complete capture without confusion
- Users express confidence data will sync
- No requests for missing critical fields

## Testing Plan
- 5 field techs
- Simulate offline scenario
- Task: Log 3 service calls
- Observe and interview

Fidelity Decision Tree

Are you testing concept/value?
  Yes → Low fidelity
  No ↓

Are you testing usability/flow?
  Yes → Low to Medium fidelity
  No ↓

Are you testing technical feasibility?
  Yes → Medium to High fidelity
  No ↓

Are you testing performance/scale?
  Yes → High fidelity

Tips

• Start lower fidelity than you think
• Focus on learning, not impressing
• Fake what you can (wizard of oz testing)
• One prototype, one primary learning goal
• Plan 2-3 iterations per idea
• Throwaway prototypes are okay
• Document what you learn, not just what you build