What and why - Design Rationale
Building trust by clearly explaining decisions with facts and solid reasoning
Nowadays I am valued as a designer.
My voice is surfacing, my thoughts are cherished, my decisions are sought after. I feel I am worthy both in my current company and outside, in my mentoring endeavours.
All of this is great, but I can trace back, with precision, to a point where I was in a completely opposite situation—and that was not long ago.
I have an assumption that since I was able to fine-tune my Design Rationale, things went in a positive direction. If you haven’t heard the term before, don’t worry—I learned it not long ago.
Some backstory
For most of my years as a designer, I’ve been “following” a blurry, confusing, and frankly unstructured list of “principles” to back my design decisions.
I knew that I should focus on user needs, I knew my designs needed to be implementable and aligned, and I knew I had to persuade peers to get them implemented.
At times, it felt as if I was gambling with my work output—sometimes I got it right on the first try, other times I completely missed the mark with a major gap.
In my personal life, I was becoming aware of how my impulsivity and lack of clarity often put me in a hard spot when explaining the reasons behind my actions. One thing was clear—I had to develop principles of reasoning to allow me to articulate all decisions I take in all domains of life.
What is Design Rationale
Design rationale is the reasoning behind design decisions.
It’s that simple. Simple, but not easy.
It is the justification behind the design decisions we make.
It’s what explains why certain choices were made, how they address user, business, and technical needs, and how they are beneficial. It’s what, often, makes or breaks a design.
My personal design rationale list follows this structure: principle and rationale. The list is heavily inspired by Dieter Rams and his timeless design principles.
1. Empathy for the user
Principle: Every design decision I make must prioritise the needs, behaviours and goals of the user.
Rationale: User as core focuses me on solving real user problems through empathy, meaning
2. Clarity and Simplicity
Principle: As simple and as clear as possible. Complexity leads to problems.
Rationale: Humans are innately drawn to simplicity. Clear, simple patterns are processed faster.
3. Consistency
Principle: Consistency in language, visuals, patterns and behaviour.
Rationale: Consistency creates familiarity, familiarity creates safety. When a product is predictable, it improves the trust and leads to better UX.
4. Data-backed Decisions
Principle: Base design decisions on research, testing, and analytics.
Rationale: Data-driven decisions validate that the design aligns with actual user needs, rather than our assumptions.
5. Scalability and Flexibility
Principle: Design with future growth and adaptability in mind.
Rationale: Scalability allows the product to grow or evolve By designing flexible systems that can accommodate new features or user needs, you ensure long-term sustainability.
Wrapping things up
In short, developing a design rationale has transformed how I approach work. It's what gave me structure to what was once instinctive, enabling me to articulate the why behind every design choice.
By focusing on empathy, clarity, consistency, data, and scalability, I’ve not only improved the quality of my designs but also my ability communicate, collaborate and influence.
Understanding what design rationale is only half the battle. You might be wondering how to put this into practice. How do you refine your own principles and use them to justify design decisions? How do you make this a habit, not just a concept?
In the next part of this series—“How: Design Rationale”—I’ll walk you through the practical steps and strategies that helped me get better at this skill. We’ll dive into methods, examples, and real-life applications that will help you build your own design rationale and apply it to every project with confidence.
Catch you next week!