Design Principles
Qualities of Effective Principles
What distinguishes principles that guide decisions from ones that gather dust
Key Insight
Effective design principles are authentic (specific to your product, not universal platitudes), actionable (you can apply them to a decision), and opinionated (they rule things out, not just in). The "opposite test": if the opposite of your principle is obviously wrong, it's too generic. "Be accessible" fails—no one advocates for inaccessibility. "Optimize for screen readers first, then enhance" passes.
Key Points
- •Authentic: specific to your product context, not universally applicable
- •Actionable: provides clear enough guidance to choose between two options
- •Opinionated: rules things out, has a reasonable opposite another company might choose
- •Memorable: short enough to recall in the moment of a decision
- •Testable: you can evaluate a design against it with a yes/no answer
Guidelines
- ✓Apply the opposite test: would anyone in good faith advocate for the reverse?
- ✓If a principle applies to every product in existence, it's too generic
- ✓Include the "why"—so team members understand the reasoning behind the constraint
- ✓Write principles as positive direction, not just prohibitions
Formula
Effective Principle = Specific Context + Clear Action + Testable Outcome
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