hooked-ux

---
name: hooked-ux
description: Use when designing habit-forming product loops (Trigger, Action, Variable Reward, Investment), re-engagement or notification strategy, streaks, or "users aren't coming back."
category: Design
version: 1.0.0
tools: []
---

# Hook Model Framework

Framework for building habit-forming products. Habits are not created — they are built through successive cycles through the Hook.

## Core Principle

**The Hook Model** = a four-phase loop that connects the user's problem to your solution frequently enough to form a habit, moving usage from deliberate to automatic:

```
Trigger → Action → Variable Reward → Investment
    ↑                                      │
    └──────────────────────────────────────┘
```

## Scoring

**Goal: 10/10.** Score the loop by the four Quick Diagnostic rows (internal trigger, dead-simple action, variable reward, investment loads next trigger): each row earns 2 (fully satisfied), 1 (partial), or 0 (absent), then `score = round(total / 8 × 10)`. Then apply the ethics gate: if the Manipulation Matrix places the product as Dealer (or it hits any "When NOT to Use" condition), cap the score at 3 regardless of mechanics. Bands: 9-10 = complete loop, internal trigger identified, ethics clear; 5-6 = loop runs but leans on external triggers or predictable rewards; ≤3 = broken loop or extractive design. Always state the current score and the diagnostic rows blocking 10/10.

## The Four Phases

### 1. Trigger

The actuator of behavior. Triggers are external (environment-driven: notifications, emails, ads) or internal (emotion-driven) — the goal is to migrate users from external to internal triggers. Every habit starts with a cue, but internal triggers — boredom, loneliness, uncertainty, FOMO — drive unprompted usage because the emotion itself fires before any reminder can. Map your product to the specific negative emotion it resolves. Effective external triggers are well-timed, actionable, and lead to the simplest possible next action. If users still need external prompts after ~30 days, no internal trigger has formed.

**Product applications:** onboarding uses external triggers to establish the first loop (welcome email with one clear action); retention maps the product to an internal emotional trigger (Instagram resolves boredom, Google resolves confusion); re-engagement bridges gaps with external triggers ("Your friend just posted a photo") until habit forms.

**Copy patterns:** "Don't miss what happened while you were away" (FOMO); "Your friend just..." (social trigger bridging to internal); "Pick up where you left off" (routine trigger).

**Ethical boundary:** don't build triggers that fire on vulnerable emotional states (depression, addiction, grief) — those users can't exercise the autonomy the loop assumes.

### 2. Action

The simplest behavior done in anticipation of a reward, guided by the **Fogg Behavior Model**: Behavior = Motivation + Ability + Trigger, all converging at the same moment. Increasing motivation is hard and unreliable; reducing friction (increasing ability) is easier and more effective. Six elements of simplicity: time, money, physical effort, brain cycles, social deviance, non-routine. The action is the simplest behavior in anticipation of reward, not the full task. Hick's Law: more choices = slower decisions; reduce options to increase action rate.

**Product applications:** signup flow minimizes fields and steps (one-click Google/Apple sign-in); core action completable in seconds (Twitter: type 280 characters and post); progressive disclosure asks for more only after the initial reward (Duolingo: play first, create account later).

**Copy patterns:** "Just one tap to..."; "No credit card required"; buttons as verbs ("Post", "Save", "Share") not "Submit" or "Continue".

**Ethical boundary:** when you simplify an action, don't strip the cost or consequence with it — a one-tap purchase must still surface the price and the commitment.

### 3. Variable Reward

The phase that keeps users coming back. Anticipation of reward — not the reward itself — creates dopamine, and rewards must be variable (unpredictable) to sustain engagement. Three reward types: **Tribe** (social validation), **Hunt** (search for resources/information), **Self** (personal mastery). The brain's dopamine system responds most strongly to anticipation of uncertain rewards — the slot machine effect. Predictable rewards lose power; finite variability eventually becomes predictable — aim for infinite variability. Autonomy is critical: users must feel in control; forced engagement backfires.

**Product applications:** social features use variable social validation (Instagram likes — you never know how many); content feeds deliver an unpredictable resource stream (infinite scroll, algorithmically varied); gamification offers accomplishment with variable difficulty (Duolingo streaks + surprise bonus challenges).

**Copy patterns:** "See what's new"; "3 people responded to your post"; "You've unlocked a new achievement!"

**Ethical boundary:** if users consistently feel worse after engaging (regret, time loss, anxiety), the reward system is extractive — avoid infinite scroll without natural stopping points.

### 4. Investment

Users invest something — time, data, effort, social capital, money — that improves the product for next use, raises switching costs, and loads the next trigger. People value what they put effort into (the IKEA effect). Investment should come after reward, not before — users invest when they feel good. Each investment should load the next trigger (posting content triggers reply notifications). Small investments compound: preferences → better recommendations → more usage.

**Product applications:** data investment (Spotify: more listening = better recommendations); content investment (Instagram posts, Notion documents users won't abandon); reputation/social investment (Airbnb host ratings, LinkedIn network).

**Copy patterns:** "Complete your profile to get better matches"; "The more you use it, the smarter it gets"; "Invite your team to collaborate."

**Ethical boundary:** investment should genuinely improve the experience — never trap users with artificial switching costs or impossible data export.

## The Habit Zone

Two axes determine if a product can become a habit:

| | Low Frequency | High Frequency |
|--|---------------|----------------|
| **High Perceived Value** | Viable product (needs ads/marketing) | **HABIT ZONE** |
| **Low Perceived Value** | Failure | Failure |

Ask: how often do users need to engage, what's the perceived value of each engagement, and is frequency high enough to form automatic behavior?

## Habit Testing

**The 5% rule:** a habit has formed when at least 5% of users show unprompted, habitual usage. Three questions: (1) **Who** are the habitual users, and what do they share? (2) **What** are they doing — the "Habit Path" that separates power users from casual users? (3) **Why** are they doing it — what internal trigger and emotion precede usage?

## The Manipulation Matrix

Framework for evaluating the ethics of habit-forming products:

|  | **Maker Uses Product** | **Maker Doesn't Use** |
|--|------------------------|----------------------|
| **Materially Improves User's Life** | **Facilitator** | **Peddler** |
| **Doesn't Improve Life** | **Entertainer** | **Dealer** |

Ask: would I use this myself? Does it genuinely help users achieve their goals? Am I exploiting vulnerabilities or serving needs?

**When NOT to use the Hook Model:** the product doesn't genuinely improve lives; you're targeting vulnerable populations (children, addiction-prone users); the business model depends on user regret; engagement conflicts with user wellbeing.

**Regulatory context:** watch children's apps (COPPA, GDPR-K), dark patterns (rising FTC enforcement), "addictive" notification practices, and loot boxes (expanding gaming rules).

## Onboarding Audit Checklist

- **First Trigger:** first action obvious and easy; right external trigger for this user; value proposition clear before asking for investment.
- **First Action:** core action completable in under 60 seconds, friction removed; UI familiar (no new learning required).
- **First Reward:** immediate feedback with a variable element (surprise, delight); reward connects to an internal trigger.
- **First Investment:** asked after reward (not before), small but meaningful; loads the next trigger.
- **Loop Completion:** clear path back to the trigger; external triggers sent at appropriate times; progression through the Hook is measured.

## Common Mistakes

| Mistake | Why It Fails | Fix |
|---------|-------------|------|
| **Relying on external triggers indefinitely** | You're renting attention, not building habits | Map product to an emotion; transition to internal triggers within 30 days |
| **Making the core action too complex** | Users drop off before the reward | Simplify to minimum viable action; apply the six ability factors |
| **Using predictable rewards** | Dopamine response fades with novelty | Add variability across tribe, hunt, and self rewards |
| **Asking for investment before reward** | Users haven't received value yet | Sequence: trigger, action, reward, THEN investment |
| **Ignoring the ethics of your hook** | User regret, backlash, regulatory risk | Use the Manipulation Matrix; be a Facilitator, not a Dealer |

## Quick Diagnostic

| Question | If No | Action |
|----------|-------|--------|
| What's the internal trigger? | Users need reminders to use it | Research user emotions |
| Is the action dead simple? | Users start but don't complete | Remove friction |
| Is the reward variable? | Users get bored | Add unpredictability |
| Does investment load next trigger? | Users don't return | Connect investment to triggers |

Based on the Hook Model developed by Nir Eyal (*Hooked: How to Build Habit-Forming Products*; companion volume *Indistractable*). Eyal taught at Stanford Graduate School of Business and the Hasso Plattner Institute of Design.