Principlev1PR-489
When building retrieval systems, limit each hierarchical…
When building retrieval systems, limit each hierarchical level to 5-8 choices and total depth to 3-4 levels, as exceeding these bounds degrades both retrieval performance and cognitive processing regardless of content quality.
Why This Is a Principle
This derives from Working Memory Capacity Limit (working memory ~4 items), Directed Attention as Depletable Resource (effortful processing depletes resources), and Hick's Law of Choice Time (decision time increases logarithmically with options). The principle follows: human cognitive architecture sets hard constraints on hierarchical navigation—too many choices per level overwhelms working memory, too many levels exhausts decision-making resources. The specific numbers (5-8, 3-4) operationalize the underlying capacity limits into actionable design constraints.