UX glossary · engl. Double Diamond
Double Diamond
The Double Diamond is a process model from the UK Design Council. It splits design work into four phases and shows when a team should think broadly and when it should commit.
Imagine a food delivery service getting more and more complaints about late orders. In the very first meeting, a solution is already on the table: a live map so customers can track their delivery. Three months later, the map is done and the complaints keep coming. The real problem was something else entirely: the kitchen was receiving orders too late.
The Double Diamond is designed to prevent exactly this kind of shortcut.
Explained simply
The Double Diamond is a model that shows a design process as two diamonds side by side. The first diamond stands for the problem, the second for the solution. Each diamond first opens up and then narrows down again.
Opening up is called divergent thinking: you explore widely, look in many directions and don’t commit yet. Narrowing down is called convergent thinking: you select, condense and make decisions. Think of planning a vacation. First you look at lots of destinations, then you pick one, then you compare several places to stay and finally book one.
The model was developed by a team at the UK Design Council, a British organization that promotes good design, led by Richard Eisermann. According to the Design Council, it was created in the early 2000s and first shared publicly in 2004. The goal was to make the design process visible to people who don’t design themselves.
The four phases
- Discover: Understand the problem instead of assuming it. That means talking to and spending time with the people affected, for example through user research.
- Define: Make sense of what you learned and reframe the challenge.
- Develop: Work out different possible solutions, ideally together with a range of people.
- Deliver: Test solutions at a small scale, drop what doesn’t work and refine what looks promising, for example with a prototype.
The diagram may run neatly from left to right, but the Design Council itself stresses that teams loop back when they learn something new. That’s why it later expanded the model into the “Framework for Innovation,” which adds principles and methods, among other things. A close relative is design thinking, which uses similar phases.
An example
Back to the delivery service. Before: the team jumps straight into the second diamond and builds the live map.
After: in the Discover phase, the team spends two evenings in the kitchen and talks to customers. In the Define phase, the challenge now reads: “Orders reach the kitchen too late.” In the Develop phase, three ideas emerge, from a tablet in the kitchen to fixed pickup windows. In the Deliver phase, the team tests the tablet in one location. Waiting times drop noticeably, and only then is it rolled out everywhere.
In practice
- Stay in the first diamond on purpose. If the solution is already fixed at the kickoff, ask which problem it’s supposed to solve and how the team knows.
- Separate collecting from deciding. If you judge ideas while collecting them, you close the diamond too early. Plan separate sessions or phases for each.
- Use the model to get everyone aligned. The two diamonds help you show clients why research takes time. For a closer look at what research involves, read What Does a UX Researcher Do?.
Related terms
Design Thinking, User Research, Prototype, Usability Testing