Build your PBL units around the ‘Double Diamond’

This article is part of our series on how to help students use critical and creative thinking to break down problems, devise & evaluate solutions, and inform their interactions with others. To learn more about how we teach critical & creative thinking, see here.

Getting the structure of a PBL unit right can go long way towards ensuring its success.

We’ve spoken previously of our preference for Design Thinking as the framework for PBL. It helps segment a long project into shorter, discrete levels; it focuses students in each level on the key outcomes for that stage of the project; and it clearly delineates the parts of the unit devoted to explicit teaching from the hands-on application of that knowledge to create a solution.

But Design Thinking is only part of the story. It helps us structure a project into levels, but it doesn’t tell us what students should be doing within each level. And that’s important, because within each level – especially the Empathise & Define and the Ideate levels – students need to display different thinking dispositions. Having something which signals this to students helps them make the cognitive adjustment from critical to creative thinking or vice versa.

So that’s where the Double Diamond process comes in. Let’s explore how it works.

What is the Double Diamond process?

The Double Diamond approach to problem solving is built around two pairs of divergent and convergent thought.

Divergent thinking is used to ‘go wide’ and explore different ideas, possibilities, and possible causes; convergent thinking is used to ‘go narrow’ and refine these possibilities down to a single cause, problem, or idea. Thinking about what you could order for takeaway through Uber Eats? That’s divergent thought. But you’ll use convergent thought to make your final choice.

The first ‘diamond’ – or pair of divergent and convergent thought – relates to the exploration of the problem. Students use divergent thought to build a 360 degree view of the problem and investigate all of its impacts, causes, and implications; they then switch to convergent thought to choose a single cause or manifestation of the problem to solve.

The second ‘diamond’ relates solely to the development of an idea or strategy to solve that problem. Students use divergent thinking to generate potential solutions to their chosen problem; they use convergent thought to evaluate those ideas and ultimately emerge with a single solution. This is the one they take into the prototyping phase of a PBL unit.

As you’ve probably gathered by now, the divergent thinking phase of either diamond generally requires creative thinking or curiosity-driven exploration. By contrast, the convergent thinking phases rely on critical thinking.

The Double Diamond & Design Thinking

What’s the difference between the two? Well, Design Thinking provides the structure for the entire unit, whilst the Double Diamond helps teachers and students identify what outcome they are working towards within that framework. This might sound like a small distinction, but it’s not. As we discussed above, helping students understand how they should be thinking at any stage across the project helps frame all the information that they take in. Learning content through explicit teaching? Well, I’m in the ‘diverging’ stage of the first diamond, so I guess this information is going to relate to one of the causes or impacts of the problem. Looking at whether or not this government policy worked? I’m in the second ‘converging’ phase – so I should probably use the lessons from what didn’t work to help me evaluate my own ideas.

Here’s how the Double Diamond process maps to Design Thinking.

Level 1

Level 1 (either Empathise & Define or Discover, depending on the project) comprises the first diamond.

Students will use divergent thought when exploring the different components and causes of the problem, and when thinking about how their curriculum knowledge helps them understand the problem from different angles.

When they reach the end of Level 1, they will generally have to summarise their learnings and define the problem as they see it, which marks their switch from divergent to convergent thinking. They need to identify the single cause or part of the problem they want to tackle and develop a solution for.

Level 2

Levels 2 & 3 (either Ideate and Prototype & Test, or Create & Share, depending on the project) make up the second diamond. Here, students are encouraged to apply what they know to generate potential solution ideas to the problem (as they have defined it) and extend them (divergent thought), before choosing a single solution to implement after carefully considering the feasibility, practicality, and likely impact of those solutions (convergent thought). 

The build/prototyping phase is an extension and the logical outcome of this double diamond approach. It technically is not part of either diamond.

What should students do in each diamond?

For each project level (and, therefore, each diamond), students will need to apply critical and creative thinking in subtly different ways:

Level 1 (first diamond)

In the diverging phase, students should:

• Develop inquiry questions to explore and better understand the problem 

• Connect learnings from explicit teaching to understand how curriculum content informs their understanding of the problem

• Build their knowledge about the problem, its impacts, and its causes

In the converging phase, students should:

• Synthesise information to identify patterns and trends

• Look for insights or opportunities which reveal the root causes driving a problem

• Evaluate and prioritise the different ways the problem could be solved

Levels 2 & 3 (second diamond)

In the diverging phase, students should:

• Explore current approaches to solving that problem

• Generate and extend their own existing solution ideas

In the converging phase, students should:

• Evaluate the feasibility and practicality of each solution idea

• Choose the one idea they’ll work on in the prototyping phase

What this means for your PBL unit

You might think this approach seems overly formulaic. Does a PBL unit really need a blend of Design Thinking and the Double Diamond?

The short answer is yes. Structuring a project using Design Thinking is great, but only if you are building the tasks within each level to specific decision points which move students forward in the project. It only helps shape students’ thinking if they have a very clear set of goals at different stages within each level that they can build their activity around. That’s what the Double Diamond gives you.

More than anything, it gives students an actionable framework to approach problem solving. Investigate a problem, look at all its causes, evaluate them and choose one to solve. Think of lots of different ways to solve that problem, evaluate those options, choose one to build our solution around. Rinse and repeat. If you can train students to think like this, they’ll reap the benefits beyond the PBL unit you’re running. They’ll have the tools to think and work their way through any problem that life throws at them.

So, when you’re building your next PBL unit, here’s a mental checklist to follow:

• How does curriculum content tie into this problem?

• Will curriculum content sit better in the first diamond or the second? Will it help students understand the problem or generate a solution?

• If the first diamond, will teaching this content help students understand a cause/impact of the problem, or will it help them compare and evaluate which cause/impact to solve?

• If the second diamond, will teaching this content help students develop possible solution ideas, or will it help students understand the criteria which can be used to evaluate ideas?

• Has sufficient time and emphasis been built in at the end of each diamond to ensure students choose a single problem to solve and a single solution idea to prototype?

Do you know an educator who might be interested in learning more about how to design a PBL unit? If so, please share this article with them!

If you are passionate about PBL and want to learn more, get in touch with us at hello@curaeducation.com. We’re always happy to exchange ideas with our PBL community!