The non-gesture path cannot be buried deeper than the gesture path, or it exists only in name

What it is

An equivalent path written into the information architecture that takes settings, then accessibility, then another page, is buried deeper than the gesture. The gesture is one wave on the home surface; the button is three levels down. For a user already failing, that path exists in name and is unreachable in fact: they have no spare gesture to “open settings,” and opening settings may itself still be a gesture. Depth asymmetry turns equivalence into a cheque that cannot be cashed.

Why it happens

Reachability is a function of discovery steps, action steps, and current capability. When the gesture is failing, current capability often does not include “another precise mid-air menu motion.” If finding the spare button still depends on the hand that already failed, both paths break at the same point. Even a touch button, placed on a panel that only appears after a wave, breaks the same way. A shallow primary path trains people not to look for another; when they need it, memory has no entrance. Nominal existence also poisons review: the checklist ticked “has an alternative,” and nobody on site can touch it at the moment of failure.

Studying it

Measure separately: steps from the main task surface to finishing the function along the gesture path, and along the non-gesture path. Then, with the gesture channel off, measure time to first find the button and abandonment. Compare a button that stays on the home surface, one that surfaces after a failure, and one that lives only in settings. Do not have the experimenter point at the button. Use a “cannot wave” constraint (holding a cup, hands in pockets) rather than a spoken “please use the button,” or you will not measure depth asymmetry.

Where it stops holding

A professional console may bury rarely used equivalents in a deeper menu if operators are trained and can still open that layer by touch when the gesture fails. One-shot users of a public screen have no such training. Legally required accessibility entries sometimes must live in system settings; the app should still provide a shallow in-app entrance at the moment of failure. Depth can be patched by auto-surfacing after failure, but if the surfacing can be dismissed and never returns, it is buried again.

Applying it

• The non-gesture entrance must not take more steps than the gesture. If it cannot stay resident, surface it on the main face after the first gesture failure and keep it for the rest of the session.
• The action that opens the spare entrance must not itself be a mid-air gesture.
• Acceptance: with both hands occupied, time finding and completing every core function. More steps than the gesture path, or more than a dozen seconds still not found, counts as unreachable, whether or not the spec says “buttons supported.”

Related

• Same group: C4.28.1 Any function carried by a mid-air gesture needs a non-gesture equivalent path · C4.28.2 The non-gesture path serves recognition failure, fatigue, and bodily difference among other failure modes · C4.28.4 The cost of providing the non-gesture path should be counted in the overall cost of the gesture design
• Adjacent: C4.25 Predefined fallback paths · C3.24 Accessible alternatives to gestures
• Search: buried alternative · reachability · nominal existence