Continuing from earlier, it might even make sense to push the dimensionalizing further…
Touch-point design is the kind of design done by specialized design in a particular medium such as graphics, ID, interaction, architecture, etc.
Touch-line = single-channel experience strategy — shaping a series of experiences within a single channel and defining the design problem for one or several touch-points within that one channel path. This is the work a user experience strategist typically does.
Touch-plane = the same thing, but defining the experience across every channel path. This is the work omnichannel experience strategy does.
(There’s a fair amount of fluidity between UX and omnichannel, and of course UX designers often do UX strategy to define their single touch-point designs.)
Touch-space = service design. Now we have intersecting actors, each with experiences and free-will all intersecting in the delivery of a service, creating in these intersections many experiences for many actors. Service design has developed and continues to develop tools able to aid understanding and shaping of these intersecting, interacting experiences.
Now service design is no longer one more scale of “zoom-out” to encompass more of one experience but a way to handle the fact that experiences are the result of experiences, and that all experiences, whether at the official front-stage (the customer) or at the back stage (always front-stage for someone!) — all these experiences matter and they all affect one another as a system.
I suppose I could use the story of Flatland as a structuring metaphor.