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03 — Depth and Hierarchy

Apple's Depth Principle

Depth is the third of Apple's three foundational design values. Apple's Human Interface Guidelines describe depth as the use of visual layers and realistic motion to impart vitality and help people understand how things relate to and flow from one another. Motion in this context is not decoration — it is explanation. (Source: Apple HIG — Foundations)

Apple's publicly published guidance on motion elaborates this principle in practical terms:

from and where they are going. Motion that doesn't follow the logic of a gesture or interaction causes confusion rather than clarity. "In nongame apps, accurate, realistic motion helps people understand how something works." (Source: Apple HIG — Motion)

motion for the sake of adding motion. Gratuitous or excessive animation can distract people and may make them feel disconnected." Brevity and precision are the marks of good feedback animation. (Source: Apple HIG — Motion)

content rather than on the same plane, creating a legible Z-axis that helps people understand what is active, what is background, and what is reachable. (Source: Apple HIG — Layout)

important information. Supplementary audio and haptic cues must be available for people who prefer or require reduced motion. (Source: Apple HIG — Motion)

can perform an action." Motion serves the Operator; the Operator does not serve the motion. (Source: Apple HIG — Motion)

Together, these guidelines describe a design philosophy in which depth and motion are in service of understanding — not spectacle.

Application to EVE Glyph Design Children's Materials

The EVE A-glyph is a layered geometric construction: a triangle, a circle, and a half-circle combine into a unified form. That layered nature is not an abstract fact — it is the pedagogical point. Teaching a child how the EVE glyph is built means teaching them to see the layers. Apple's depth principle provides the framework for how to do that with motion.

Reveal layers with motion that explains. When a child taps a glyph element in the A-glyph exercise, that tap should trigger an animation that reveals the element's geometric origin. The triangle could expand outward from a point. The circle could draw itself. The half-circle could arc into place. Each motion should follow the logic of how the shape is constructed — not a decorative bounce or fade, but a motion that shows the shape being built. The child sees the layer arriving, and the seeing is the teaching.

Sequence layers, do not layer them all at once. Following Apple's principle of brevity and precision in animation, each construction step should animate one layer at a time, in a sequence that a child can follow. The previous layer remains visible (it is now context), and the new layer arrives with enough emphasis to be distinct. This mirrors how Apple uses visual layering to show relationships between states.

Make depth optional, not required. Some children will use these materials on devices with Reduce Motion enabled, or in environments where animation is distracting. The depth and layering should be comprehensible in static form as well — through color, outline weight, or positional callouts — so that no child is locked out of understanding because the animation is unavailable.

Short animations, always. Following Apple's guidance on precision, each layer-reveal animation should last no longer than the moment of recognition — the instant the child's brain identifies what just appeared. Animations that are too long teach the child to wait rather than to watch.

Sources:

© 2026 Dany Theriault. EVE "digital stem cell" glyph and glyph-based design principles — all rights reserved. Stewardship of rights of use and assignment for large public and institutional usage rests with the Pacific Utilities Design Council. Published as a time-stamped record of authorship and intent.

© 2026 Dany Theriault. EVE “digital stem cell” glyph and glyph-based design principles — all rights reserved. Stewardship of rights of use and assignment for large public and institutional usage rests with the Pacific Utilities Design Council. Published as a time-stamped record of authorship and intent.
pour le bien-être du peuple

Pour le bien-être du peuple. · EVE Glyph Design — Education