Part III: Design Patterns Library

Behavioral Design

Designing for sustained health behavior change
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The most beautiful app in the world won’t improve health if patients don’t use it. Behavioral design applies psychological insights to create products that motivate sustained health behavior change.

Self-Determination Theory in Health Apps

Self-determination theory identifies three universal psychological needs:

NeedWhat It MeansDesign Pattern
AutonomyFeeling in control of choicesGoal setting, customizable experience, opt-in features
CompetenceFeeling capable of successProgressive challenges, skill-building, positive feedback
RelatednessFeeling connected to othersPeer support, caregiver integration, clinician connection

Intrinsic vs. Extrinsic Motivation

Move beyond gamification to intrinsic motivation:

  • Extrinsic (points, badges, leaderboards): Works short-term but can undermine long-term motivation
  • Intrinsic (autonomy, mastery, purpose): Drives sustainable behavior change
  • Design approach: Use intrinsic motivation as the foundation. Add extrinsic elements sparingly and strategically.

Just-in-Time Interventions

Behavior change happens in moments, not sessions:

  • Context-aware: Deliver interventions when and where they’re most needed
  • Real-time adaptation: Adjust based on user state, environment, and history
  • Micro-interventions: Small, actionable steps rather than overwhelming plans
  • Moment of decision: Intervene at the moment of choice, not after

Habit Formation for Health

Design for habit formation using the habit loop:

  1. Cue — A trigger that initiates the behavior (time of day, location, notification)
  2. Routine — The behavior itself (logging a meal, taking medication)
  3. Reward — The benefit the user gets (satisfaction, data, progress visualization)

For health habits, focus on making the routine as easy as possible and the reward as immediate as possible.

Avoiding Gamification Traps

Common pitfalls in health behavioral design:

  • Empty badges: Rewards that don’t connect to meaningful outcomes
  • Shame mechanics: Public comparison that discourages rather than motivates
  • All-or-nothing streaks: Streak-based motivation that demoralizes after one miss
  • Over-engineering: Complex behavior change frameworks that users ignore