Principlev1
Each intermediate level should reduce options to 5-12 items;
Each intermediate level should reduce options to 5-12 items; if a level presents more, split it; if it presents fewer, consider removing the level.
Why This Is a Principle
Derives from Working Memory Capacity Limit (working memory ~4 items), Hierarchical Chunking Expands Capacity (chunking expands capacity), and Hick's Law of Choice Time (Hick-Hyman Law—decision time increases logarithmically with options). This principle operationalizes the 'concave shape' finding from usability research.