--- title: "Double Diamond" url: "https://www.insideuxdesign.com/en/glossar/double-diamond" language: "en" description: "What is the Double Diamond? A plain-language guide to the Design Council’s four phases, with an example and tips. Learn how to use it in your project." published: "2026-10-14T15:19:43+02:00" updated: "2026-10-14T15:19:43+02:00" --- # 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. - **Buchstabe:** D - **Englischer Begriff:** Double Diamond 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 1. **Discover:** Understand the problem instead of assuming it. That means talking to and spending time with the people affected, for example through [user research](https://www.insideuxdesign.com/en/glossar/user-research). 2. **Define:** Make sense of what you learned and reframe the challenge. 3. **Develop:** Work out different possible solutions, ideally together with a range of people. 4. **Deliver:** Test solutions at a small scale, drop what doesn’t work and refine what looks promising, for example with a [prototype](https://www.insideuxdesign.com/en/glossar/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](https://www.insideuxdesign.com/en/glossar/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?](https://www.insideuxdesign.com/en/blog/what-does-a-ux-researcher-do). ## Related terms [Design Thinking](https://www.insideuxdesign.com/en/glossar/design-thinking), [User Research](https://www.insideuxdesign.com/en/glossar/user-research), [Prototype](https://www.insideuxdesign.com/en/glossar/prototype), [Usability Testing](https://www.insideuxdesign.com/en/glossar/usability-testing) ## Sources - [Design Council: History of the Double Diamond. Design Council](https://www.designcouncil.org.uk/our-resources/the-double-diamond/history-of-the-double-diamond/) - [Design Council: The Double Diamond. Design Council](https://www.designcouncil.org.uk/our-resources/the-double-diamond/) - [Cat Drew: The Double Diamond: 15 years on. Design Council, 2019](https://www.designcouncil.org.uk/our-work/projects-programmes/archive/article/double-diamond-15-years/) ## More terms [ ### A/B Testing An A/B test is an experiment that shows two versions of a page or element at the same time to randomly split groups of visitors. It lets you decide with real data which version works better. ](https://www.insideuxdesign.com/en/glossar/a-b-testing) [ ### ARIA ARIA is a W3C standard that adds roles, states and properties to HTML. It tells screen readers what an element is and how it currently behaves. ](https://www.insideuxdesign.com/en/glossar/aria) [ ### Accessibility Accessibility means designing websites, apps and digital documents so that everyone can use them, including people with visual, hearing, motor or cognitive disabilities. ](https://www.insideuxdesign.com/en/glossar/accessibility) [ ### Affordance An affordance describes what action an object makes possible and whether people can recognize it: a button invites you to press it, a handle invites you to pull. ](https://www.insideuxdesign.com/en/glossar/affordance) [ ### Alt Text Alt text is a short text version of an image, stored in the HTML alt attribute. Screen readers read it aloud so people who can’t see the image get the same information. ](https://www.insideuxdesign.com/en/glossar/alt-text) [ ### Atomic Design Atomic Design is a method for building user interfaces from small, reusable building blocks, from single elements like buttons all the way up to complete pages. ](https://www.insideuxdesign.com/en/glossar/atomic-design) [ ### BFSG The BFSG, Germany’s Accessibility Strengthening Act, has required many companies since 28 June 2025 to make certain products and digital services, such as online shops, accessible. ](https://www.insideuxdesign.com/en/glossar/bfsg) [ ### Card Sorting Card sorting is a research method in which people sort terms written on cards into groups. It shows you how they mentally organize content, so you can plan navigation that makes sense to them. ](https://www.insideuxdesign.com/en/glossar/card-sorting) [ ### Cognitive Load Cognitive load is the mental effort it takes to understand and use an interface. The less unnecessary thinking a design demands, the easier the actual task becomes. ](https://www.insideuxdesign.com/en/glossar/cognitive-load) [ ### Color Vision Deficiency A color vision deficiency means someone has a harder time telling certain colors apart than most people. The most common type is red-green deficiency. ](https://www.insideuxdesign.com/en/glossar/color-vision-deficiency) [ ### Contextual Inquiry Contextual inquiry is a research method where you observe and interview people in their real work environment. It shows you how they actually get tasks done, not just how they describe it. ](https://www.insideuxdesign.com/en/glossar/contextual-inquiry) [ ### Contrast Ratio The contrast ratio describes how much two colors differ in brightness, such as text and background. WCAG requires at least 4.5:1 for normal text. ](https://www.insideuxdesign.com/en/glossar/contrast-ratio)