Cognition & learnability — router

This plugin holds the principles that govern how easily a user can understand, learn, and remember an interface. They are framework-agnostic and apply equally to web apps, mobile apps, desktop software, control panels, in-car displays, and printed forms.

Principles in this plugin

Each principle has its own skill (with sub-aspect skills where useful). Principles marked [full] have reference-grade skill files; the rest are planned and will be added in subsequent passes.

Complexity reduction

• hicks-law [full] — decision time grows with the log of the number of options.
  • Sub-skills: hicks-law-menus, hicks-law-defaults, hicks-law-pricing.
• 80-20-rule — 80% of usage flows through 20% of features; design the default for the 80%.
• chunking — group items into ~4±1 chunks so working memory can hold them.
• performance-load — total cognitive + kinesthetic effort to do a task; minimize both.
• progressive-disclosure — show only what's needed now; reveal advanced controls on demand.
• satisficing — users pick the first acceptable option, not the optimal one.
• ockhams-razor — among solutions that work, prefer the simplest.

Mental models and recognition

• mental-model — users come with a model of how the system works; design to match it.
• recognition-over-recall — recognizing is easier than remembering; show options.
• visibility — features that aren't visible aren't used.
• mapping — controls map onto what they affect.
• constancy — visual properties remain stable across state changes.
• iconic-representation — pictures are recognized faster than words but only when conventional.
• mimicry — borrow successful familiar patterns rather than invent.
• rosetta-stone — pair a known referent with a novel concept.

Chunking, scanning, and memory

• inverted-pyramid — most important info first, then supporting detail.
• five-hat-racks — five ways to organize: Location, Alphabet, Time, Category, Hierarchy.
• advance-organizer — a structural preview before content (TOC, breadcrumbs).
• serial-position-effects — first and last items are remembered best.
• stickiness — memorable, concrete content earns repeat use.
• storytelling — narrative encodes meaning more memorably than bullets.
• picture-superiority-effect — images outlast text in memory.
• mnemonic-device — explicit memory aids reduce recall cost.
• propositional-density — meaning per visible mark; high density reads as polished.

Wayfinding and navigation

• wayfinding [full] — orienting, choosing routes, monitoring progress, recognizing destinations.
  • Sub-skills: wayfinding-physical-spatial-metaphors, wayfinding-search-and-recovery, wayfinding-breadcrumbs-and-context.
• progressive-disclosure [full] — show what's needed now; tuck the rest behind explicit affordances.
  • Sub-skills: progressive-disclosure-defaults-and-tucking, progressive-disclosure-disclosure-affordances.

Consistency and encoding

• consistency — same things look and behave the same.
• cognitive-dissonance — contradictions between expectation and behavior cost trust.
• confirmation-bias — users notice what confirms their model and ignore what doesn't.
• comparison — comparison is easier than evaluation.
• depth-of-processing — interactive engagement yields better memory than passive reading.
• priming — exposure shapes how a subsequent stimulus is processed.
• framing — how information is framed changes the choice users make.
• modularity — break complex systems into independent, recombinable units.
• redundancy — multiple independent signals make critical info reliable.

Heuristic for which to read first

• Designing a long form or settings page → chunking, progressive-disclosure, hicks-law, mental-model.
• Picking defaults → satisficing, 80-20-rule, hicks-law-defaults, framing.
• Picking an icon set → iconic-representation, recognition-over-recall, mimicry.
• Designing a dashboard → propositional-density, chunking, inverted-pyramid.
• Onboarding → mental-model, advance-organizer, depth-of-processing, storytelling.
• Search / navigation IA → wayfinding, recognition-over-recall, five-hat-racks, visibility.
• "Users keep getting lost" → wayfinding, wayfinding-breadcrumbs-and-context, wayfinding-search-and-recovery.
• Settings / forms feel overwhelming → progressive-disclosure, chunking, hicks-law.
• Reviewing a confusing flow → mental-model, cognitive-dissonance, consistency.

Cross-plugin pointers

• For visual layout and grouping, see perception-and-hierarchy-principles.
• For behavior (errors, undo, target sizing, feedback), see interaction-and-control-principles.
• For aesthetic and tonal decisions, see aesthetics-and-emotion-principles.
• For accessibility, see process-and-robustness-principles.