---
title: "Foundation Sprint Founding Hypothesis: Brainshelf Book Catalog (Day 2 End)"
description: "Brainshelf Founding Hypothesis: canonical sentence, 6-row assumption scorecard, and Design Sprint as recommended next test."
artifact: foundation-sprint-founding-hypothesis
version: "1.0"
repo_version: "2.15.0"
skill_version: "0.1.0"
created: 2026-05-14
status: sample
thread: brainshelf
context: "Brainshelf Day 2 end Founding Hypothesis; Design Sprint week of May 26 recommended"
---

<!-- PM-Skills | https://github.com/product-on-purpose/pm-skills | Apache 2.0 -->

## Scenario

The Brainshelf team is in Day 2 end of their Foundation Sprint. Magic Lenses is signed; top bet (Yellow Camera) and backup (Red Bookstore) are named. Jamie invokes `tool-foundation-sprint-founding-hypothesis` to compress the full sprint output into the capstone artifact.

## Founding Hypothesis

> **If we help people who read 25 or more books a year and treat their personal library as memory rather than identity solve "I can't remember what I've read or what I want to read next" with sub-3-second camera-first capture into a private library, they will choose it over Goodreads, StoryGraph, paper journals, and doing nothing because our solution is the fastest way to capture a book and the most useful way to recall what they have read.**

Slot derivation:

- Target customer: 25+/year readers, books-as-memory framing (from Basics)
- Important problem: forgetting what they have read / want to read (from Basics)
- Approach: sub-3-second camera-first capture into a private library (Yellow / Approach A from Magic Lenses)
- Alternatives: Goodreads, StoryGraph, paper journals, doing nothing (from Basics competitor map)
- Differentiators: fastest capture + most useful recall (from Differentiation)

## Assumption Scorecard

| # | Assumption | Why it matters | Current confidence | Best next test |
|---|---|---|---|---|
| A1 | 25+/year readers are switchable from "do nothing" with sub-3-second capture | If false, no capture-speed product can win this segment | Medium | Design Sprint Friday testing (5 customers) |
| A2 | Camera-OCR + cover-recognition can achieve sub-3-second resolution at acceptable accuracy | If false, the differentiation collapses | Medium-high | Thursday prototype build with real OCR API |
| A3 | "Personal recall" is a strong-enough draw without social features | If false, customers churn after initial novelty | Medium | Test recall flow with prototype; post-test interview |
| A4 | Target customer can be reached through organic channels (Riley's network, content) | If false, CAC pressure forces premature monetization | High | Founder-led growth test post-DS |
| A5 | Paid sync + cross-device monetization model resonates | If false, business model unclear | Medium | Concept-pricing question in Friday script |
| A6 | "Did I already read this?" is felt strongly enough to drive recall use cases | If false, the personal recall pillar is weaker than thought | High | Friday context-question on recall scenarios |

**Highest-risk assumption:** A1. The product depends on it more than any other; the Design Sprint exists to test it.

## Why We Believe This

1. **22 customer interviews surfaced the same two pains repeatedly:** forgetting books and friction with current tools. The Founding Hypothesis directly addresses both.
2. **Riley's network is a credible distribution channel** for the target segment; warm intros tested in the readiness assessment.
3. **The team's existing capabilities** (Alex on fast-capture UX, Sam on mobile and offline) match the chosen differentiators with evidence.
4. **The "do nothing" baseline is high** for this segment, meaning a 10x-better tool can win without displacing an entrenched competitor.
5. **The differentiation is observable to customers** (speed, recall) rather than internal-team metrics (architectural elegance).

## What Could Prove Us Wrong

1. **Customers nod but don't capture.** "Yes, this looks fast" in interviews but no usage in real life within 7-day follow-up.
2. **OCR accuracy is below acceptable.** Customers see 1-in-5 mis-resolutions and lose trust.
3. **Personal recall is a feature, not a habit.** Customers capture once and never come back to recall.
4. **Camera-first is awkward in real contexts.** People feel weird scanning books at home or in public.
5. **Reading 25+/year segment is too small.** TAM-too-narrow for a venture-scale company.

## Recommended Next Validation Step

**Next step:** Design Sprint week of 2026-06-01.

**What it tests:** A1 (switchable from "do nothing") first; A2 (OCR accuracy) via the Thursday prototype build; A3 (personal recall draw) via the Friday recall flow test; A5 (pricing) via the Friday Five-Act Interview Act 5 debrief.

**Owner:** Jamie (founder, PM); Riley owns customer recruiting.

**Timeline:** Sprint begins Monday 2026-06-01; Friday testing 2026-06-05; Decider call by 16:30 Friday; 7-day instrumented follow-up through 2026-06-12.

**Decision the next step unlocks:** Build (6-week MVP cycle starting Monday 2026-06-08), iterate (refine prototype + re-sprint), pivot to backup (Red Bookstore Mode), or stop.

## Decider Checkpoint

**Decider sign-off required to close the Foundation Sprint.**

- [x] Jamie ratifies the Founding Hypothesis sentence verbatim.
- [x] Jamie confirms the 6-row assumption scorecard.
- [x] Jamie commits to running a Design Sprint week of 2026-06-01 as the next test.
- [x] Jamie acknowledges the backup plan (Red Bookstore Mode) is real, not theoretical.
- [x] Jamie acknowledges the team will not re-litigate the social-reader direction without explicit invalidation evidence from the Design Sprint.

**Signed:** Jamie (founder, PM), 2026-05-14 16:55 PT.

**Foundation Sprint closed.**
