Decision Making Decision method

Assumption Surfacing

Assumption Surfacing turns hidden conditions for success into testable assumptions and explicit learning moves.

Assumption Surfacing identifies statements that must be true for an initiative to succeed. The team separates assumptions from evidence, scores impact and uncertainty, then selects the riskiest assumptions for testing.

Core question

Which unproven assumption would endanger the initiative most if it were false?

Plan Method guide

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Participants: 2-8 participants
Time: 60–90 minutes for surfacing and prioritisation; tests follow separately

Paper illustration of an assumption matrix with prioritized test cards

Frame
Bound the initiative
Establish success, scope and the central decision as the shared reference.
Surface
State assumptions
Expose hidden conditions as specific statements that evidence could disprove.
Score
Score the risk
Assess impact if false and current uncertainty as separate dimensions.
Prioritise
Select critical assumptions
Choose high-impact, high-uncertainty assumptions as immediate learning risks.
Test
Define the learning move
Specify evidence, threshold and decision consequence before testing.

After each test, update evidence and uncertainty; a disproved assumption triggers a change or stop decision.

A good fit when

For new products, strategies or decisions whose success depends on unproven beliefs about people, markets, feasibility or operations.

Ideal for

Product Discovery
Strategy Work
Decision Readiness

Not good for

Routine decisions
Problems without an action option

Outputs

Assumption register
Categorised statements with evidence status, impact and uncertainty.
Learning plan
Prioritised tests with signal, threshold, owner, date and decision consequence.

Assumption Surfacing · Risk Matrix

Fictional example

The table separates assumption, evidence, impact, uncertainty and next learning move.

Assumption Surfacing · Risk Matrix
Item	Assumption	Evidence status	Impact	Uncertainty	Next test
A-07State a falsifiable assumption and add scores plus the learning move.	60% of weekend visitors want audio on their own phone.	No direct evidence	5/5: production decision affected	5/5: internal belief only	30 interviews plus QR prototype; threshold 18 interested and 25% starts

1. Assumption
A-07
60% of weekend visitors want audio on their own phone.
2. Evidence status
A-07
No direct evidence
3. Impact
A-07
5/5: production decision affected
4. Uncertainty
A-07
5/5: internal belief only
5. Next test
A-07
30 interviews plus QR prototype; threshold 18 interested and 25% starts

Scores are fictional judgements on a 1–5 scale, not measured values.

RAND: Assumption-Based Planning

First step

Bound the initiative and success so participants can complete the sentence “For this to work, it must be true that …”.

Open the method guide

Where to go next?

Product Discovery

Riskiest Assumption Test

Runs the planned learning step for the riskiest assumption.

Growth

Growth Experiment

Turns the assumption test plan into a measurable experiment.

Deep dive

Purpose

Plans often contain assumptions that were never openly stated and remain dangerous precisely because of that. Assumption Surfacing makes these silent premises visible and prioritizes which of them carry the initiative or could sink it.

How it works

Implicit assumptions are collected and sorted by uncertainty and influence. The sorting separates mere expectations from statements that need to be checked with data, experiments, or research. This makes uncertainty manageable before it becomes expensive.

In detail

Assumption Surfacing makes the silent beliefs behind plans, options, or conflicts visible. Assumptions must be distinguished by significance and uncertainty rather than just collected. Value emerges when the riskiest assumptions turn into tests, decisions, or deliberate bets.

Facilitation

Write assumptions down as testable statements and separate the obvious from the risky premises while doing so. The insight leap comes when hidden premises with high impact and low certainty lie openly on the table. End the pass with a sequence for validation, observation, or deliberate acceptance.

The method guide walks execution through 5 phases, timing, 5 pitfalls, and clear stop criteria.

Open method guide

Your perspective

Does this method help with your work?

Your feedback helps shape the next improvements to methodatlas.

Sources and topics

Topics

Assumptions Risk Decision Discovery

Sources

Assumption-Based Planning: A Tool for Reducing Avoidable Surprisesrand.orgPrimary source by Dewar and colleagues on load-bearing assumptions and signposts.Testing Business Ideasstrategyzer.comAuthor-led source on hypotheses, experiments, evidence and learning decisions in product work.

Artifact templates

Assumption Surfacing: WorksheetBound the initiative and success so participants can complete the sentence “For this to work, it must be true that …”.

markdown

assumption-surfacing-working-template.md

Bound the initiative and success so participants can complete the sentence “For this to work, it must be true that …”.

Assumption Surfacing: Worksheet

Question

To be confirmed

Desired outcome

To be confirmed

Scope

Complete workflow Time: 60–90 minutes for surfacing and prioritisation; tests follow separately

Complete this worksheet on paper or in your own document during the work.

Preparation for this scope

Method setup

Materials: Decision or concept sketch, existing research, assumption cards and an impact-uncertainty matrix.
Roles: Initiative owner, domain experts for value, feasibility and operations, plus a facilitator.
Advance information: Audience, desired outcome, solution idea, commercial and operational conditions and available evidence.
Overall time needed: 60–90 minutes for surfacing and prioritisation; tests follow separately
Setup: Prepare collection areas for desirability, viability, feasibility and usability plus a prioritisation matrix.

Prepare for the work steps

Frame: Bound the initiative

Initiative sketch
Goal and decision

Surface: State assumptions

Test frame
Value, business, technical and operational perspectives

Score: Score the risk

Assumption cards
Existing evidence

Prioritise: Select critical assumptions

Scored matrix
Time and decision need

Test: Define the learning move

Prioritised assumptions
Access to data or participants

Assumption Surfacing · Risk Matrix

Item	Assumption	Available evidence	Impact if false	Uncertainty	Test, threshold and consequence
A-07

A-07: State a falsifiable assumption and add scores plus the learning move.

Use one assumption per row. Justify impact and uncertainty separately; examples stay out of the blank worksheet.

RAND: Assumption-Based Planning

Frame: Bound the initiative

Expected artifact: Test frame

Initiative, success, scope and decision

Entry:

...

Is it clear what could change if an assumption is false?

Surface: State assumptions

Expected artifact: Assumption cards

Statement, category and current evidence

Entry:

...

Could observable evidence disprove the statement?
Does each card contain one assumption?

Score: Score the risk

Expected artifact: Scored assumption matrix

Impact, uncertainty and rationale

Entry:

...

Were impact and uncertainty scored independently?
Is high confidence backed by evidence?

Prioritise: Select critical assumptions

Expected artifact: Prioritised assumptions

Rank, decision link and owner

Entry:

...

Would a negative result trigger a change?
Is the set small enough for the next learning cycle?

Test: Define the learning move

Expected artifact: Assumption test plan

Method, signal, threshold, owner and consequence

Entry:

...

Does the test address exactly one assumption?
Are responses to support and disproof predetermined?

Open questions and next steps

...

Method guide: https://methodatlas.meierhoff-systems.de/en/methods/assumption-surfacing/run-sheet

Alternatives and neighbors

Fitting alternatives with decision guidance, followed by other related methods.

All methods

Paper illustration of a calm four-quadrant Assumption Map with hypothesis cards and emphasis on important assumptions with little evidence.

Product Discovery

Assumption Mapping

Instead of Assumption Surfacing, when you want to make assumptions visibly prioritized before starting with solutions.

A hypothetical failure makes concrete risks, signals, and fitting mitigations visible.

Decision Making

Pre-Mortem

Thinks through failure in advance to surface risks, countermeasures, and critical assumptions early.

Decision Making

Risk Matrix

Moves options, criteria, and risks toward a concrete result through "set the scales for likelihood and impact", "collect risks or carry them over from earlier identification", and "define actions for each high-risk item".