Illustration must not carry the action
Aliases: non-action illustration · decorative illustration · false affordance
What it is
A button-shaped object, an arrow, a lit switch inside a scene will be tapped as a control. Illustration may warm emptiness and mood. It may not hide the next step in the drawing. Action — where to go, what to hit, what will happen — belongs on real controls and sentences. Drawing the action into the illustration builds a fake button with no hit area and no accessible name.
Why it happens
People probe by affordance: things that look like buttons get tapped; things that look like wayfinding get followed. To look busy, illustrations often show a figure at a door, a hand reaching for a switch, a sign with writing on it. In a picture those are narrative. In an interface they are a promise. A dead tap is not "enjoying the composition"; it is a failed action. Worse, when the real button is less conspicuous than the fake one in the drawing, attention lands first on the thing that cannot run. Stroke, shadow, and volume all raise affordance, which is exactly why illustration must not carry operations: visually, it is too much like a thing.
Studying it
Log first taps on an empty or welcome page. Count taps that land inside the illustration where no control exists as false-affordance taps. Independents: whether the drawing contains button shapes / arrows / hands, and the area of the real button relative to the art. Dependents: false-affordance rate, time to the real button. Eye tracking is optional; a heatmap is enough. If the false-affordance rate stays up after the real button's copy is rewritten, the picture is the problem, not the words.
Where it stops holding
- If the whole illustration is intentionally one large button, with control chrome and an accessible name, the action is not "carried by illustration"; a control is wearing an illustration skin, and it must be tested as a button.
- A purely decorative scene with no control-like objects draws fewer false taps. Doors, switches, and signs bring the risk straight back.
- This does not decide whether illustration belongs on an empty page, or how heavy the file is. It only asks whether the drawing is issuing an action.
Applying it
- Strip objects that read as controls: fake buttons, lone arrows, reaching hands, in-picture type. Actions live only on real buttons and real sentences.
- Keep the real button outside the scene, looking like the other buttons on the page.
- How to check: plot first-session taps on the illustration. A cluster with no responder means remove the object being tapped from the drawing — do not give the art an invisible hot zone.