When we try to make sense of a complex situation in our heads--something at work, something in our lives--it's hard. There's this consideration here, but then there's that fact over there. We need to lay that information out somehow, but it can't be just a simple listing; we have to organize it and make sense of it as a whole.

Think about it: Even packing for a trip is easier if you can spread everything out on the bed to eyeball and then organize. For thinking about things, you can lay it out physically, in piles of papers and sticky notes and arrows. The writer John McPhee wrote about how he arranged his research for long articles or books out on an enormous table, so he could have a sense of the narrative flow, how things fit together, and where there might be holes. Describing how he developed the narrative structure for his article, Encounter with an Archdruid, involving dams in the West and the Sierra Club and geologists, among other actors, he wrote:

When I was through studying, separating, defining, and coding the whole body of notes, I had thirty-six three-by-five cards, each with two or three code words representing a component of the story. All I had to do was put them in order. What order? An essential part of my office furniture in those years was a standard sheet of plywood—thirty-two square feet—on two sawhorses. I strewed the cards face up on the plywood. The anchored segments would be easy to arrange, but the free-floating ones would make the piece. I didn’t stare at those cards for two weeks, but I kept an eye on them all afternoon. Finally, I found myself looking back and forth between two cards. One said “Alpinist.” The other said “Upset Rapid.” “Alpinist” could go anywhere. “Upset Rapid” had to be where it belonged in the journey on the river. I put the two cards side by side, “Upset Rapid” to the left. Gradually, the thirty-four other cards assembled around them until what had been strewn all over the plywood was now in neat rows.

So, spreading everything out isn't enough, you still have to make sense of it. Edward Tufte, the guru of the visual display of information, criticized PowerPoint for, among other things, how it spread out information. On the second page of his indictment, he said, "Visual reasoning usually works more effectively when the relevant information is shown adjacent in space within our eyespan.” A failure to provide this kind of information can have serious consequences: Tufte's discussion on pp. 38-52 of his book Visual Explanations of how a failure to display causally-related information contributed to the Challenger disaster is a classic. Putting relevant, causal relationships in a single eyespan helps us think. 

We design our workshops with this guideline in mind, so people can "see it all at once to make sense of it," whatever "it" might be--how their team works together, what their values are, what their plans and problems are. And every time, people are amazed at what their world looks like when they can see it laid out in one place.