Perceptual Congruence

A design principle for accessible representations that requires the structure of a non-visual interface (such as a screen reader navigation tree) to mirror the visual structure of the original graphical representation. A perceptually congruent screen reader structure preserves the same groupings, hierarchies, and adjacency relationships that sighted readers perceive through visual Gestalt principles. For example, if a stacked bar chart visually groups data both by team (through spatial proximity) and by competition (through colour alignment), a perceptually congruent accessible structure should allow users to navigate through both groupings. Perceptual congruence has two key properties: it is domain-agnostic (applying across different types of charts, diagrams, and visual representations) and it supports fluid traversal (enabling concise, reversible navigation).