A museum considering collection changes to attract a more diverse audience might assume that the intended communities will value those changes enough to engage. Assumption mapping separates that belief from assumptions about resources, delivery, access, and possible harm, then compares each assumption’s importance with the strength of evidence supporting it. This gives a team a way to decide what to investigate before committing resources.
The Five Categories
Desirability: Beliefs about what people want or value
Viability: Beliefs about resources and sustainability
Feasibility: Beliefs about technical or operational possibilities
Usability: Beliefs about how people will interact
Ethical: Beliefs about impacts and implications
The Four Quadrants
Plot each assumption on two axes: How important is this to success? and How strongly does relevant evidence support it? Consider how closely the evidence matches the people, situation, and decision in question. Evidence that contradicts an important assumption calls for revising the proposal, regardless of how much evidence has been collected.
Weak or Uncertain Support | Strong Support | |
|---|---|---|
High Importance | 🔴 Leap of Faith: Test these first | 🟢 Supported Assumptions: Document and monitor |
Low Importance | 🟡 Quick Checks: Test if easy | ⚪ Supported Low Priority: Move on |
30-Minute Mapping Session
List assumptions (10 min): Ask: What must be true for this to succeed? Generate as many as you can without filtering.
Plot the important ones (10 min): Select your top 5–7 assumptions. Place each on the matrix. Treat the initial placement as provisional; note the evidence and any disagreements.
Plan next steps (10 min): For each "leap of faith" assumption, identify one way you might test it. Could be a conversation, observation, small experiment, or desk research.
Testing Methods by Effort
Quick (hours): Desk research, asking colleagues, reviewing past data
Medium (days): Informal conversations with visitors/stakeholders, reviewing comparable cases
Deeper (weeks): Structured interviews, observation protocols, pilot programs
Source: Adapted from Teresa Torres, Evaluating Solutions: The 5 Types of Assumptions that Underlie Our Ideas (Product Talk, 2023).
Connects to: Value of Information.