It strikes many as kind of odd, but architects and designers can't think unless they are sketching something, making things, or trying things on their computers. The essence of designing is exploring an idea by putting it to paper, or materializing it, and reflecting on what it becomes while the sketching/making is done. No designer knows exactly what he is sketching, but while he is sketching he explores ideas, is surprised by what happens before him, and responds to what emerges. In time, the idea develops, expressed through sketches and models with more details and more choices. Thinking is no longer confined to the boundaries of the brain but includes the sketches or models the designer is working on.

A good metaphor is that of a painter who is painting. The painter has an idea of what he wants to paint, but when painting he is not painting exactly what he has 'in mind', but responds to the painting as it develops in time. He paints, steps back to reflect, paints more, reflects, adapts, reflects, and so on. He adds another layer on top of the first and reflects how the layers and colors respond to each other. Ideas are abandoned when they don't work out nicely, and the painter paints over them. Unintended 'errors' look suddenly very good and become leading for progressive painting.  The painter, the paint, the brushes, and the canvas together not only enable the development of the painting but are a cognitive system. Take away the paint or the brush, and the painter can't 'think'. 

For developing an idea to a concept, the ongoing development of representations is central. Not just to document what is decided on, but to explore ideas and adapt them in action, just like the painter is painting.

To develop individual ideas for the Future of Food exhibition, different developers used different media.
Food artists responsible for developing examples of 'future tastes' experimented with recipes, trying to find a balance between jaw-dropping experiences, acceptable cost, and scalability.

Developers of exhibits sketched in their notebooks, used dedicated design software, and often used large foam board panels and Duct-tape to make (very) rough 1:1 models to get a 'feel of size'. The communication designers worked with specialized software, using many 'Lorus Ipsum' texts and 'placeholder images' while developing their ideas, making prints the size of posters.

The web designer chooses to develop wireframes first that depict the structure of a website. He was carefully mapping where textual and visual information would be depicted and how to navigate through the extensive supporting website they had in mind, even though he had no clue what the copywriters would come up with.