Tasks / Challenge

1000x an idea

Can the model expand an idea's ambition while keeping it tethered to a real mechanism?

Measures the systemTask v1.0 · 2 casesDifficulty

What AI gets right here, and what you’ll still have to catch

From 3 graded outputs by 2 models. 67% were usable with at most a quick edit.

Reliably right

  1. Addresses the actual decision100% pass
    The memo commits to a clear call (approve the one-quarter scope with holdout test) and says what would change it (if the retention test shows no lift, invest elsewhere).
    Opus 5.5 · Claude · Sharing a shopping list, 1000x
  2. Identifies material uncertainty100% pass
    It names the key uncertainty (whether sharing causes the retention gap or is selection) and proposes a randomized holdout test to resolve it, with clear actions for each outcome.
    Opus 5.5 · Claude · Sharing a shopping list, 1000x
  3. Extreme, then back to buildable100% pass
    It pushes the dimension of household coordination to an extreme (household OS, every member, predictive rhythm, location coordination) and works back to a concrete, buildable first step that tests the same mechanism.
    Opus 5.5 · Claude · Sharing a shopping list, 1000x

Where it slips

  1. Proposes tests that could fail42% pass
    The retention test lacks a numeric threshold for 'meaningfully better', and the duplicate-purchase metric only says 'fall sharply' without a specific number, so the tests do not have the required numeric thresholds.
    Opus 5.5 · Claude · Sharing a shopping list, 1000x
  2. Produces the required deliverable75% pass
    It is a memo for Marcus and the exec team and covers the required sections, but it is not within the requested length and is not usable without trimming.
    Opus 5.5 · Claude · From tip calculator to worker network
  3. Avoids unsupported claims75% pass
    It presents extrapolated beta worker counts, ask volumes, and current routing gaps as facts without labelling them as assumptions.
    Opus 5.5 · Claude · From tip calculator to worker network

Case viewer

Read the brief, then put up to three outputs side by side, each with the LLM judge’s verdict on every check. Highlights mark what a PM had to fix.

The brief

You're a PM at Pantry. Aisha, one of our PMs, has proposed letting people share a shopping list with one partner. Before we commit next quarter to it, our CEO, Lena Brandt, wants to see the 1000x version: how big could this idea get? Write a memo for Lena and Aisha of no more than 700 words that takes the idea to its most ambitious version and then back to what we should build first, and how we'll know it's working. What we know is below.

About PantryA shopping-list app. 2.4 million monthly active users, free, with a $4.99-a-month Plus plan that 3% of users pay for. The team for this work: four engineers and a designer, for one quarter.
Aisha's proposal“Let a user invite one partner to a list. Both can add and tick off items.”
What we already seeSome users already share their login with a partner to get the same effect. Lists edited from two or more devices on different phone numbers: 11% of lists. Users whose list is edited from two or more devices keep using Pantry at month 3 at 71%, against 22% for everyone else. On those lists, 38% of items are added by the second device. The most common support request is 'we both bought the milk': 1,900 tickets last quarter about duplicate purchases.
What hasn't workedRecipes and meal plans launched a year ago; 4% of users have opened them in the last month. Lena's note: “Whatever we do, it probably needs AI in it.”
ConstraintLegal: we can't track anyone's location without an explicit opt-in from that person, and we can't show one person's location to another without the second person's opt-in too.
What a strong answer does

Finds the mechanism in the data: the value is several people coordinating one household's shopping (71% against 22% month-3 retention when a list is edited from two devices, 38% of items added by the second person, 1,900 duplicate-purchase tickets), not the list itself and not recipes (4% use them). Pushes that one dimension to the extreme, such as the list as the household's shared memory where everyone's needs flow in, nobody double-buys and each errand goes to whoever is best placed (with location only on opt-in from both people), rather than adding AI features for their own sake. Works back to a first step four engineers can ship in a quarter that tests the coordination mechanism: shared lists for the whole household (not just one partner) with a live 'I'm at the shop' claim so items aren't bought twice. Sets a threshold, such as the share of lists with a second active editor and duplicate-purchase tickets per shared list, and says what result would stop the bigger bet. Uses AI only where it serves coordination, if at all.

Critical failures (cap the score)
  • Builds the ambitious version on recipes, meal plans or AI for one person, dropping household coordination
  • Proposes tracking or sharing a person's location without their explicit opt-in
Case

v1.0 · synthetic · B2C, consumer app, retention, ambition

Usable with a quick edit9 of 10 checks passed

The memo is complete and evidence-based; a PM could quickly add numeric thresholds to the test criteria without redoing any reasoning.

Output

To: Lena Brandt and Aisha Subject: From shared lists to a household coordination layer

Thesis: Don’t think of this as a sharing toggle. Treat it as a wedge into making Pantry the place a household coordinates what it needs and who is getting it.

The 1000x version

Today, Pantry remembers a list. At its most ambitious, it remembers a household’s preferences and routines, helps everyone keep that shared memory up to date, and coordinates the next step: what’s running low, who’s picking it up, and how to avoid buying it twice. Over time, that could become a trusted AI household assistant—able to turn “we’re out of oat milk” into an editable list item, learn preferred brands, and suggest replenishment. With permission, it could eventually connect that plan to retailers or fulfillment.

AI belongs here as a useful assistant, not a badge: it can interpret messy requests and learn household patterns, but people stay in control of the list and any purchase. Location is not required for the core experience; any future location feature must follow Legal’s opt-in requirements for both people.

What to build first

Aisha’s proposal is the right wedge. In one quarter, build a reliable, account-based shared list for two people:

  • Invite a partner with their own account; both can add, edit, and check off items in near real time.
  • Show who added or checked off an item, with a simple “I’m getting this” state to reduce duplicate purchases.
  • Add basic duplicate warnings and notification controls; never silently merge or remove items.

Keep recipes, retailer integrations, automatic purchasing, location, and a broader household product out of scope. Once the shared-list flow works, test one contained AI feature—natural-language item entry that produces an editable item and quantity. The shared list must work just as well without it.

There’s a real signal: 11% of lists are already edited from multiple devices, and 38% of items on those lists come from the second device. The 71% versus 22% month-three retention gap is striking, but it’s observational, not proof that sharing causes retention. The 1,900 duplicate-milk tickets last quarter give us a concrete problem to solve.

How we’ll know

Run a randomized rollout to eligible users, comparing an invitation to use shared lists against a control. Judge impact across everyone offered the feature—not just people who accept—so we avoid mistaking high intent for product impact.

Track: - Adoption: invite acceptance and the share of invited households with two active contributors each week. - Core outcome: duplicate-purchase reports per 1,000 shared-list weeks, plus duplicate-related support tickets. - Business outcome: incremental month-three retention versus control. - Guardrails: sync failures, unwanted notifications, and privacy or account-access incidents.

Agree on go/no-go thresholds before launch. If sharing drives sustained two-person use, reduces duplicates, and improves retention in the randomized test, we have evidence to expand from “shared list” toward the household assistant. If not, we should fix the collaboration basics before adding more ambition.

Check by check

Got wrong · 1
  • Proposes tests that could failThe output does not set numeric thresholds for the go/no-go criteria; it only says to agree on them before launch.
Got right · 9
  • Uses the supplied evidence correctlyAll factual claims about the current situation are directly supported by the supplied context.
  • Addresses the actual decisionThe memo commits to a clear first step and states what results would lead to expanding or stopping the bigger bet.
  • Respects explicit constraintsThe memo is under 700 words, respects the legal opt-in requirement for location, and proposes a scope feasible for the given team and quarter.
  • Identifies material uncertaintyIt identifies that the retention gap is observational and not proof of causation, and says a randomized test will resolve whether sharing improves retention.
  • Avoids unsupported claimsInterpretations like the retention gap being observational are clearly labelled, and no confident claims go beyond the evidence.
  • Produces the required deliverableThe memo is addressed to Lena and Aisha, within the word limit, and provides a complete, actionable plan.
  • Finds the mechanism in the dataHousehold coordination is named as the mechanism, backed by the supplied figures, and kept central to both the extreme version and the first step.
  • A first step that tests the big ideaThe shared list with 'I'm getting this' state fits the team and quarter, directly tests coordination, and includes a clear stop/continue condition.
  • Extreme, then back to buildableThe memo pushes the idea along the household coordination dimension to an extreme version, then works back to a concrete, buildable first step.

Grades and run details

Decision model 90 · LLM judge 10 of 11 checks
Decision model checks
  • passUses the supplied evidence correctly79%
  • passAddresses the actual decision65%
  • passRespects explicit constraints37%
  • passIdentifies material uncertainty65%
  • passAvoids unsupported claims54%
  • partialProduces the required deliverable39%
  • passFinds the mechanism in the data74%
  • passA first step that tests the big idea65%
  • passExtreme, then back to buildable94%
  • partialProposes tests that could fail82%
Run
Run
#1
API response time
30 s
Submitted
30 Sept 2026

Results

Every setup we’ve tested on this task, across all cases and repeats, graded on the current checklist. Provisional The checklist is still being calibrated against our PM.

#Model · HarnessTask scoreDecision modelLLM judgeRunsCritical failures
1GPT-6 LunawithAPI90.090.91None
2Opus 5.5withClaude93.074.62None

About the task

The PM job

Finding the bigger version of a good idea.

Why it matters

Ambition without mechanism is fan fiction. The useful version pushes to the extreme, then works back to something buildable.

What good looks like

  • Names the mechanism that scales
  • Keeps the core insight
  • Works back to a first step you could build

Deliberately not measured

    Capability tested

    Ambitious expansion

    The failure we’re looking for

    Bigger adjectives, same idea

    Grading

    Decision model and LLM judge, calibrated against a blind PM review

    This task measures the whole setup. Tools, instructions and skills in the harness do real work here, so read the harness as carefully as the model name.