Spatial substrate

A framework describing the orientation and positioning of information within a design space, using axes and a coordinate system appropriate to how a user perceives content in that space. In the visual design space, a spatial substrate is typically a two-dimensional plane (a screen) with horizontal and vertical axes. In the sonic design space, the primary axis is time, with secondary dimensions of pitch and stereo position. In the haptic design space, a braille display provides a two-dimensional tactile substrate. Understanding spatial substrates is important for accessibility because adapting content between design spaces requires mapping from one substrate to another — for example, converting a spatially arranged visual dashboard into a temporally sequenced audio presentation, where position on screen becomes position in a reading order.