design-rationale
The design-rationale skill guides designers in documenting the reasoning behind design decisions through a structured seven-part framework: decision, context, options considered, evidence, reasoning, trade-offs, and validation plan. Use this skill when making major design choices, departing from established patterns, addressing controversial decisions, or anticipating future questions about design direction to create decision documentation that connects to user needs and business goals.
git clone --depth 1 https://github.com/Owl-Listener/designer-skills /tmp/design-rationale && cp -r /tmp/design-rationale/designer-toolkit/skills/design-rationale ~/.claude/skills/design-rationaleSKILL.md
# Design Rationale You are an expert in articulating the reasoning behind design decisions. ## What You Do You write clear design rationale that connects decisions to evidence, principles, and goals. ## Rationale Structure ### 1. Decision What design decision was made? Be specific about what was chosen. ### 2. Context What problem or need prompted this decision? What constraints exist? ### 3. Options Considered What alternatives were explored? Brief description of each. ### 4. Evidence What informed the decision? User research, data, best practices, competitive analysis, usability testing. ### 5. Reasoning Why this option over the alternatives? Connect to user needs, business goals, design principles, and technical feasibility. ### 6. Trade-offs What are the known compromises? What was deprioritized and why? ### 7. Validation Plan How will you know if this decision was right? What metrics or feedback will confirm? ## When to Write Rationale - Major design direction decisions - Departures from established patterns - Controversial or debated choices - Decisions that will be questioned later - Changes from previous approaches ## Rationale Quality Checklist - Connects to user needs (not just designer preference) - References evidence or principles - Acknowledges alternatives and trade-offs - Is specific enough to be useful months later - Written for the audience who will read it ## Best Practices - Write rationale during the decision, not after - Keep it concise but complete - Store rationale alongside the design files - Reference in handoff documentation - Use rationale in design reviews to explain choices
Design an A/B experiment — hypothesis, variants, primary metric, and sample size. Use when a change can be measured quantitatively at scale. For observing behaviour qualitatively, use `test-scenario`.
Audit an existing interface against WCAG, producing findings with severity ratings and remediation steps. Use when you have a design or build to assess now. Not for planning future sessions with assistive-technology users — use `accessibility-test-plan` (prototyping-testing).
Plan accessibility testing — assistive technologies, participant criteria, WCAG coverage, and session protocol. Use when scheduling testing with real AT users. Not for evaluating a design yourself — use `accessibility-audit` (design-systems).
Apply the Aesthetic-Usability Effect — polished, consistent interfaces are perceived as more usable and forgive minor friction. Use when justifying visual polish or diagnosing why a functional design tests badly. For emotional resonance specifically, use `interfaces-that-feel` (interaction-design).
Cluster many qualitative data points into themes and insight statements. Use when synthesising across multiple sessions or sources. For a single transcript use `summarize-interview`; for one segment's inner state use `empathy-map`.
Apply animation principles — easing, staging, follow-through — to one specific UI motion. Use when tuning how an animation feels. For product-wide duration and easing tokens use `motion-system` (design-systems); for a full interaction spec use `micro-interaction-spec`.
A practitioner's toolkit for thinking and communicating as a designer in a business context — reading financials, mapping competitive landscapes, and defending design decisions in the language of value.
Analyse open or closed card sort results into a proposed grouping and label set. Use after running a sort study. For turning that evidence into a full structure, use `information-architecture` (ux-strategy).