Risky Assumption
A risky assumption is an assumption that is critical to the success of an idea but for which teams have little evidence.
How do you identify risky assumptions?
Risky assumptions are evaluated based on two factors:
1. Importance: How critical is this assumption to the success of the idea?
2. Evidence: How much evidence do you already have that this assumption is safe?
When teams engage with customers regularly, most assumptions don't carry much risk—they're mostly safe. Teams only need to test the riskiest assumptions that could torpedo their ideas or cause harm to customers or the company.
What types of risky assumptions should teams assess?
Teams assess assumptions along multiple dimensions:
- Desirability: Will customers want this?
- Viability: Can we build a sustainable business around this?
- Feasibility: Can we build this with our resources and constraints?
- Usability: Can customers use this successfully?
- Ethical: Could this cause harm to customers or society?
How do you test risky assumptions?
Teams "de-risk" their ideas by running assumption tests to collect evidence about whether risky assumptions are safe.
The process:
1. Identify your riskiest assumptions
2. Ask: "What data would convince you this assumption is or isn't risky?"
3. Design the smallest possible test to collect that evidence
4. Use the evidence to determine if the assumption is safe
Clear identification of risky assumptions helps teams design focused, efficient tests rather than conducting extensive research on every assumption.
Why does identifying risky assumptions matter?
Teams can take bigger risks with experiments when decisions are reversible (two-way door decisions). If you can easily undo a decision, it's safer to try ambitious solutions that might have more upside but also more potential for failure.
The key is ensuring leaders understand and accept the level of risk the team is taking.
Learn more:
- Assumption Testing: Everything You Need to Know to Get Started
Related terms:
- Assumption Testing
- Research
- Solutions
Last Updated: October 25, 2025