# Evidence Packet: Desirable Difficulty Case Study

**Version:** 1.0  
**Date:** 2024-02-21  
**Designer:** Robert Duebelbeis

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## Scope

This evidence packet supports the behavioral design case study: "Desirable Difficulty — Behavioral Design for Health Compliance."

**Problem:** Bob needs to reduce coffee consumption per doctor's orders while on blood pressure medication.

**Intervention:** Manual pour-over ritual introducing desirable difficulty (skilled friction) to transform habitual consumption.

**OEC:** Cups per week (primary) with satisfaction ≥4.0 SEQ (guardrail)

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## Contents

| File                         | Description                                                                                                                                                                                                                                                                                                                                                                  |
| ---------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `01_readme.md`               | This file — scope, OEC, version                                                                                                                                                                                                                                                                                                                                              |
| `pre_registrations.csv`      | **Append-only** hypothesis log (CI-enforced)                                                                                                                                                                                                                                                                                                                                 |
| `02_assumption_map.csv`      | All assumptions with certainty/importance ratings                                                                                                                                                                                                                                                                                                                            |
| `03_trace_matrix.csv`        | DI ↔ verification method ↔ evidence link ↔ status                                                                                                                                                                                                                                                                                                                            |
| `04_diary_protocol.md`       | Daily log template, weekly interview guide                                                                                                                                                                                                                                                                                                                                   |
| `05_observation_protocol.md` | Session recording consent, coding rubric                                                                                                                                                                                                                                                                                                                                     |
| `06_decision_log.csv`        | Timestamped decisions with rationale                                                                                                                                                                                                                                                                                                                                         |
| `07_automation_flow.md`      | iOS Shortcut design: flow diagram, step detail                                                                                                                                                                                                                                                                                                                               |
| `diary_events.csv`           | 172 coffee_consumption events — a RECONSTRUCTED export, not the original device log (which was not retained). Generated to reproduce every weekly_aggregates column exactly, on nominal 7-day study weeks from 2024-01-06; the study's own week ledger drifted and its printed end date (2024-02-21) precedes the nominal Week 8 — a recorded spread this file does not hide |
| `observation_events.csv`     | 8 observation_session events with behavioral codes                                                                                                                                                                                                                                                                                                                           |
| `weekly_aggregates.csv`      | Weekly roll-ups for all metrics                                                                                                                                                                                                                                                                                                                                              |
| `phase_summary.json`         | Phase comparisons and effect sizes                                                                                                                                                                                                                                                                                                                                           |
| `cross_validation_log.csv`   | Weekly validation checks (diary vs observation)                                                                                                                                                                                                                                                                                                                              |
| `velocity_events.csv`        | SLICE/EPIC completion events for velocity tracking                                                                                                                                                                                                                                                                                                                           |
| `pr_events.csv`              | PR merge events for lead time tracking                                                                                                                                                                                                                                                                                                                                       |
| `bp_log.csv`                 | Weekly blood-pressure readings — exploratory only                                                                                                                                                                                                                                                                                                                            |
| `physician_clearance.md`     | Week 4 continuation clearance (2024-01-27)                                                                                                                                                                                                                                                                                                                                   |
| `forecast_latest.md`         | Monte Carlo forecast with confidence intervals                                                                                                                                                                                                                                                                                                                               |

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## Study Design

**Type:** Single-subject ABA (baseline–intervention–washout)

| Phase            | Duration  | Purpose                              |
| ---------------- | --------- | ------------------------------------ |
| A — Baseline     | Weeks 1–2 | Establish ground truth consumption   |
| B — Intervention | Weeks 3–6 | Test desirable difficulty hypothesis |
| A — Washout      | Weeks 7–8 | Test habit transfer                  |

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## Primary Outcome

| Metric             | Baseline | Post-Intervention | Change |
| ------------------ | -------- | ----------------- | ------ |
| Cups/week          | 32       | 18                | −44%   |
| Satisfaction (SEQ) | 4.0      | 4.2               | +0.2   |

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## Falsification Criteria (Defined A Priori)

The hypothesis **fails** if:

- [ ] Weekly cups do not decrease by ≥20% by Week 4
- [ ] Satisfaction drops below 3.0/5.0 average
- [ ] Participant abandons before Week 6
- [ ] Consumption rebounds to baseline during washout

**Result:** All criteria passed.

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## What This Doesn't Prove

Look, n=1 is n=1. I'm not claiming this generalizes. But it does show:

- The method (daily logging + observation coding) is executable
- Pre-registration prevents p-hacking myself
- Effect held through washout (not just novelty)

Things I can't rule out:

- Hawthorne effect (being observed changes behavior)
- The BP meds might've helped motivation
- 8 weeks isn't forever

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## Notes

Data anonymized for portfolio. Raw video deleted per protocol.

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*bob@duebelbeiss.com*