[Phillipharryt]

?? Touchscreen interfaces almost always have contextual displays. So no touching it doesn't always do the same thing every time I press it. The space where a spacebar is on your phone is the same space that is sometimes the camera button. I think contextual design does not suit important interfaces.

[bumby]

I meant it in terms of pressing a working contextual display. I think we're saying the same thing. Software introduces many more failure pathways so it's often not suitable for primary hazard mitigation.