These rules represent convergent truths discovered independently across cognitive psychology, industrial design, human-computer interaction, and perceptual research. Each principle appears in multiple disciplines—evidence of genuine universality. Together, they form an irreducible foundation for creating excellent products and experiences.

Perception: How humans see and organize information

1. Group related elements through proximity, similarity, and enclosure. Elements placed close together, styled alike, or bounded together are perceived as a unit. Separate unrelated items with whitespace. (Gestalt psychology, 1910s; applies to every visual medium)

2. Establish clear visual hierarchy through size, contrast, and position. Larger, higher-contrast, higher-positioned elements attract attention first. The eye follows predictable scan patterns (F-pattern for text, Z-pattern for minimal layouts). (Eye-tracking research; visual design fundamentals)

3. Ensure sufficient contrast and unambiguous figure-ground relationships. Users must instantly distinguish interactive elements from background and primary content from secondary. When this fails, everything fails. (Gestalt figure-ground; WCAG perceivability)

Cognition: How humans think; process, and decide

4. Minimize cognitive load—remove every non-essential element. Every piece of information competes for limited mental resources. Eliminate extraneous content ruthlessly. What remains gains power. (Cognitive Load Theory; Nielsen’s “Aesthetic and Minimalist Design”; Rams’ “As little design as possible”)

5. Favor recognition over recall—make options and actions visible. Humans recognize far more easily than they remember. Never require users to recall information from one screen to use another. Show, don’t expect memorization. (Nielsen #6; cognitive psychology; menu vs. command-line research)

6. Chunk information into groups of 4–7 items maximum. Working memory holds roughly 4 items reliably (7 at maximum). Break long lists, complex forms, and dense content into digestible clusters. (Miller’s Law, 1956; chunking research)

7. Limit choices at each decision point. Decision time increases logarithmically with options. Too many choices cause paralysis, abandonment, and regret. Curate and sequence decisions. (Hick’s Law, 1952; Paradox of Choice research)

8. Reveal complexity progressively—show essentials first, details on demand. Start with the minimum needed to accomplish primary tasks. Let users access advanced features when they need them, not before. (Progressive disclosure; Tognazzini; reduces both cognitive load and error rate)

Interaction: How humans act on systems

9. Make targets large and place them close to likely cursor/finger position. Time to acquire a target = f(distance ÷ size). Bigger, closer targets are faster and less error-prone. Screen edges and corners have infinite effective width. (Fitts’s Law, 1954—one of the most replicated findings in HCI)

10. Give users control and easy, obvious reversal of actions. Enable Undo everywhere. Reversibility reduces anxiety, encourages exploration, and builds confidence. Users should feel like initiators, not responders. (Nielsen #3; Shneiderman #6; Tognazzini; Norman)

11. Prevent errors through constraints; when errors occur, enable clear recovery. Design interfaces so mistakes are difficult or impossible. When they occur anyway, explain the problem in plain language and offer a specific solution—never error codes. (Nielsen #5 and #9; Shneiderman #5; Norman’s constraints)

12. Support multiple methods and paces of interaction. Provide accelerators (shortcuts, automation) for experts while maintaining simple paths for novices. Accommodate different physical abilities, input methods, and speeds. (Nielsen #7; Shneiderman #2 “Universal Usability”; Inclusive Design)

Feedback: How systems communicate back

13. Respond instantly (< 100ms) to direct manipulation. This threshold creates the perception that the user—not the computer—caused the result. It’s essential for the feeling of direct control. (Response time research; Nielsen/Norman; Tognazzini)

14. Provide immediate feedback for every action, proportional to its significance. Minor actions need subtle acknowledgment; major actions need substantial confirmation. Silence after user action creates uncertainty. (Nielsen #1; Shneiderman #3; Norman’s feedback principle; Apple HIG)

15. Display progress indicators for any operation exceeding 1 second. The 1-second threshold marks where flow breaks. At 10 seconds, attention shifts elsewhere. Show progress bars (not just spinners) for longer operations—users need to know how long to wait. (Response time thresholds; Nielsen; Tognazzini #12)

16. Reinforce critical feedback across multiple sensory channels. Combine visual, auditory, and haptic cues for important events. This redundancy improves perception, supports accessibility, and strengthens the experience. (Multisensory integration research; Universal Design #4 “Perceptible Information”)

Consistency: How systems build predictability

17. Follow platform conventions—users’ expectations are set by other products. People spend most time elsewhere. Match established patterns for navigation, interaction, and terminology. Violate conventions only with clear purpose and strong signaling. (Nielsen #4; Jakob’s Law; Apple HIG; Shneiderman #1)

18. Maintain internal consistency—identical actions should always work identically. Same visual style, same terminology, same behaviors throughout. Inconsistency forces users to relearn and erodes trust. (Shneiderman #1; Tognazzini’s consistency levels)

19. Create natural mappings between controls and their effects. The spatial arrangement of controls should correspond to the arrangement of what they affect. Good mappings make operation feel intuitive without learning. (Norman’s “natural mappings”; industrial design)

Clarity: How systems reveal themselves

20. Make affordances visible through clear signifiers. Affordances are what actions are possible; signifiers communicate where and how to act. Every interactive element must visually indicate its interactivity. If users can’t find a feature, it doesn’t exist. (Norman; Gibson; Tognazzini’s discoverability)

21. Align the interface with users’ existing mental models. People predict behavior based on prior experience. Design should match what users already believe about how things work. Test for mental model mismatches—they cause the deepest confusion. (Mental models research; Norman’s conceptual model)

22. Design sequences with clear beginnings, middles, and endings. Structure interactions as complete episodes. Provide informative closure when tasks finish—it creates satisfaction, relief, and orientation for what comes next. (Shneiderman #4 “Design Dialogs to Yield Closure”; Peak-End Rule)

Essence: The foundational stance

23. Be honest—never manipulate or promise what you cannot deliver. The interface should be exactly what it appears to be. Don’t make products seem more capable, innovative, or valuable than they are. Trust is the foundation of continued use. (Rams #6 “Good design is honest”; Apple’s “Aesthetic Integrity”)

These principles are timeless because they are grounded in human physiology and psychology—not technology or trends. Working memory won’t expand. Fitts’s Law won’t reverse. Visual perception follows the same Gestalt rules it did a century ago. Build on these foundations, and your designs will endure.