Musings by @thedevel

Lean UX Notes: Part 1

368 words · 11 May 2013

This is Part 1 of a series of posts on various notes and takeaways from the book Lean UX: Applying Lean Principles to Improve User Experience focusing on Core Elements, Assumptions, and Hypotheses.

Core Elements

Definitions are quoted directly from the book.. because they are good.

  • Assumptions - A high-level declaration of what we believe to be true.
  • Hypotheses - More granular descriptions of our assumptions that target specific areas of our product or workflows for experimentation.
  • Outcomes - The signal we seek from the market to help us validate or invalidate our hypotheses. These are often quantitative but can also be qualitative.
  • Personas - Models of the people for whom we believe we are solving a problem.
  • Features - The product changes or improvements we believe will drive the outcomes we seek.



Every project starts with assumptions, but usually we don't explicitly acknowledge this fact. Instead, we try to ignore assumptions, or worse, treat them as facts. ... Declaring assumptions allows your team to create a common starting point. ... It reveals the team's divergence of opinions and also exposes a broad set of possible solutions.

Preliminary Questions

  • how is the current product being used in lieu of the issue?
  • were their any past attempts to fix the issue? (successes and failures)
  • how have/are other products handling this issue?

Problem Statement

Define (and agree upon) a problem statement as a starting point. Include:

  • Statement (assessment) of the goals of the product
  • All known constraints
  • Statement of improvement (independent of the solution)

Risk Assessment & Prioritization

Simply, what are the risks associated with each assumption?

The higher the risk, the greater need to test or address the assumption.

         high risk
known ----------------- unkown
          low risk


Test Assumptions

The general template:

We believe [this statement is true]. We will know we're [right/wrong] when we see the following feedback from the market: [qualitative feedback] and/or [quantitative feedback] and/or [key performance indicator change]

This method removes subjective and political influence from the assessment and decision-making.