Sketch-thinking

Presentation drawing — the polished render you show a client — is a skill that takes years. Thinking drawing — the rough, fast, ugly sketch you make for yourself while figuring something out — requires almost no skill; a child can do it, nobody sees it. The first communicates a finished idea; the second generates the idea. This lesson is the second kind.

The mind has a tiny workbench (Simon's bounded rationality) — try to mentally arrange seven rooms with their adjacencies, the sun, and circulation and your head overflows. The sketch is external memory: it holds the whole arrangement outside your skull. The hand makes the vague specific — the pencil won't let an idea stay fuzzy, and that forced specificity is where you discover problems ('if the prayer corner is there, it blocks the only window'). And the eye answers back — you draw, you look, and the drawing tells you something you didn't know you knew. This draw-see-react-redraw loop is the design method made physical, sped to seconds.

A blob is a space or activity. An arrow is movement, sightline, the sun, or a force. A thick line is solid (a wall); a thin/dashed line is soft or movable (a screen, a 'maybe'). A squiggle is texture or 'stuff here, figure it out later.' A stick figure reminds you of scale and reintroduces the body and persona. A section cut lets you think in the vertical dimension the plan hides. The most useful technique is trace paper — sketch, lay a fresh translucent sheet on top, draw the next version, keep what works; the iteration loop made physical.

The computer is a converging tool — it demands precision before you're ready, makes things look finished before they're good (triggering premature attachment), and is slow to change radically. It pressures you to settle. The hand is a diverging tool — fast, loose, comfortable with vagueness, free to throw away, and it resists polish. The rule: sketch by hand to diverge; move to the computer to converge. Jumping to the computer too early kills ideation.