Assumption Mapping
A technique for systematically identifying, categorizing, and prioritizing the assumptions behind a product idea to determine what needs testing first.
Also known as: Assumption Testing, Leap of Faith Assumptions
Category: Techniques
Tags: product-management, product-discovery, risk-management, techniques, validation, experimentation
Explanation
Assumption Mapping is a structured technique used in product discovery to surface and prioritize the hidden assumptions that underlie any product idea or solution. Every product decision rests on assumptions — about customer behavior, market dynamics, technical feasibility, and business viability. The danger lies not in having assumptions, but in being unaware of them.
**How it works:**
The process typically involves two dimensions plotted on a 2x2 matrix:
1. **Importance**: How critical is this assumption to the success of the idea? If this assumption is wrong, does the whole idea fall apart, or is it just a minor detail?
2. **Evidence**: How much evidence do we already have? Is this assumption well-supported by data, or is it based on gut feeling?
Assumptions that are both highly important and lacking evidence are the **leap-of-faith assumptions** — these should be tested first.
**Types of assumptions to identify:**
- **Desirability assumptions**: Customers have this problem. Customers want this solution. Customers will switch from their current solution.
- **Viability assumptions**: Customers will pay this price. We can acquire customers at this cost. This fits our business model.
- **Feasibility assumptions**: We can build this with available technology. We can build this within our timeline. We have the skills needed.
- **Usability assumptions**: Customers can figure out how to use this. Customers will complete the key workflow. The learning curve is acceptable.
**Why it matters:**
- Prevents teams from investing heavily in solutions built on untested assumptions
- Focuses experimentation efforts on the highest-risk areas first
- Makes implicit team beliefs explicit and debatable
- Reduces confirmation bias by forcing teams to articulate what could go wrong
- Aligns the team on what needs to be true for an idea to succeed
Assumption mapping is a key practice within the Opportunity Solution Tree framework, where it sits at the bottom level — connecting proposed solutions to the experiments that will validate them.
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