Perplexity Knowledge Base UX Research

Perplexity Deep Research report (April 2026) on navigation and UX best practices for a read-only knowledge base serving a non-technical CEO. Covers landing page design, navigation architecture, search UX, mobile design, page-level elements, information scent, and accessibility.

Key Facts

Landing Page

• Search + category cards + single featured update recommended. Recognition-based navigation dominates for non-technical intermittent users (NNGroup). 5 categories is within the 5–7 cognitive sweet spot.
• Each card: icon, plain-language title, 1–2 sentence description, page count. Descriptions must avoid taxonomy language (“Companies, people, and organisations we track” not “Entity taxonomy”).
• Pattern mirrors Notion help center, Shopify help center, Confluence knowledge bases.

Navigation Architecture — Four Layers

• Layer 1 (global): Search bar + breadcrumbs on every page.
• Layer 2 (landing): Search + 5 category cards.
• Layer 3 (category landing): Optimised per content volume — Concepts (102 pages) needs sub-domain grouping (operations, strategy, finance, governance, marketing, technology); Sources (50) needs filterable table; Entities (19) needs alphabetical card grid; Decisions (7) and Analysis (4) show all items on one screen.
• Layer 4 (content page): Left sidebar scoped to current category with current page highlighted.
• Maximum 3 hierarchy levels: Home → Category → Page. Disorientation threshold at 2–3 levels (NNGroup).

The Unequal Category Problem

• 15/102/50/7/4 distribution. Concepts at 102 pages (57% of content) needs secondary subdivision. Decisions and Analysis are small but high-value — keep them visible, don’t fold into larger categories. Source: NNGroup IA research.

Search UX

• Inline modal pattern (results as user types) outperforms full-page results. Show title, breadcrumb path, highlighted excerpt, content-type label. Limit to 5–8 visible results.
• Cmd+K is gold standard but must be supplemented with visible clickable search (non-technical user may not know keyboard shortcut).
• For “vague recall” searches: manually maintained synonym/alias map in search config rather than vector search at this scale.

Mobile Design

• Off-canvas left drawer (not bottom tab bar). Slides in from left as overlay, animates 200–300ms, dismiss on tap-outside or swipe-left.
• Touch targets: 44×44pt minimum (Apple HIG). Search input must use ≥16px font or Safari auto-zooms.
• Do NOT implement custom swipe-to-open-drawer (conflicts with Safari back gesture).
• PWA worth implementing — 178 pages typically <10MB compressed, iOS home screen PWAs avoid 7-day cache eviction.

Page-Level UX (Essential)

• Breadcrumbs (single most important orientation cue — GOV.UK research)
• Sticky scroll-aware table of contents in right rail (desktop) / collapsed accordion (mobile)
• Last updated timestamp (trust signal for business intelligence content)
• Related pages section at bottom (3–5 cross-referenced pages — prevents “dead patch” abandonment)
• Page type coloured label (Entity, Concept, Decision, Analysis, Source Summary)
• Anchor links for each heading

Graph View Assessment

• Full 178-node graph = “visual hairball” — non-expert users can’t extract actionable information (Mayr et al. 2022). Local diagram (current page + direct connections, 5–15 nodes) adds genuine value. Keep full graph as authoring/maintenance tool only.

Typography and Accessibility

• Body text: 18–19px desktop, 16–17px mobile. System font stack (-apple-system). Line length: max-width: 65ch. Line height: 1.5×.
• Colour contrast: 1a1a1a on ffffff (not pure black — reduces eye strain). WCAG AA minimum 4.5:1.
• Dark mode: off-black (#121212) on off-white (#e0e0e0), increase font weight one step. Follow prefers-color-scheme.

Implementation Priority Matrix

Priority	Elements
P0	Search + category card landing, collapsible sidebar, breadcrumbs, responsive layout, 18px body text
P1	Pagefind search modal, sticky TOC, related pages footer, page type labels, last updated timestamp
P2	PWA, reading time estimate, Cmd+K, print stylesheet, dark mode
P3	Local graph view, previous/next navigation

Exemplar Sites

Top transferable models: GOV.UK (plain language), Stripe Docs (search + category layout), Shopify Help (dense category columns), Notion Help (sidebar + cards), MDN Web Docs (TOC + section-scoped sidebar), Apple Support (card grid for non-technical users).

Related Pages

• Mat Wiki Access Implementation — decision page synthesising all three research reports
• Mat O’Keefe — target user of the wiki viewer