6.4. How to consolidate ideas
In any creative process, once you have enough ideas someone has to look at the possibilities and divide them into useful piles. This makes it possible to understand the different viable design directions and to begin to see their differences. (As a rule, 4 or 5 piles of things are easier to work with than 30, 50, or 150 individual things. This is true for ideas, specifications, hyperactive children, small animals, pieces of candy, annoying writers that make silly lists for no reason, etc.) It's fine if some ideas are represented in prototypes and others in scribbles, notes, or unexplored thoughts. The goal isn't to eliminate or refine individual ideas, it's to put some shape and structure around them all.
There are many techniques(3) for doing this, but the simplest one I know is an affinity diagram (a.k.a. KJ diagrams, after the anthropologist Kawkita Jiro). This approach requires four things: ideas, a wall, Post-it notes, and the team (although good beer and tasty food help). In an affinity diagram, each idea is represented as a note, described in just a few words and placed on the wall. These ideas can be the output of brainstorming sessions or a list refined by one or more people on the team. There can be anywhere from 20 to 100 or more ideas. The scope of the problem you're trying to solve, and how creative people have been, can make for wild swings in the size of ideas from project to project.
With an affinity diagram, you'll see a broader view ...