KNOWLEDGE NOTES

Knowledge Notes

Explore curated knowledge, course notes and methods, with their existing content and sources preserved.

This index lists complete English editions. Additional Chinese notes and bilingual updates remain available in the Chinese index.

350knowledge notes
Product Design & UX / NNGroup User Experience

NNGroup Visual Design Principles: Gestalt Grouping, Visual Hierarchy, Typography, Color, Imagery (19 articles · Five core visual principles / Gestalt proximity-similarity-closure-common region / Visual hierarchy-grid-golden ratio / Typography terminology-pairing-readable typefaces / 60-30-10 color rule / Picture superiority effect-photography-imagery / Aesthetic-usability effect / Glossary)

19 curated core articles from the Nielsen Norman Group visual design principles subset. One core thread breaks "looking good" down into "working well": ① The five overarching visual principles (Scale, with a maximum of 3 size levels; Visual Hierarchy; Balance, covering symmetrical, asymmetrical and radial types; Contrast; Gestalt) form the master framework. ② The four Gestalt grouping principles: Proximity (the strongest grouping cue; split a 12-field form into 3 groups of 4), Similarity (color > shape > size for conveying grouping, with counterexamples of misleading similarity), Closure (the brain fills in missing parts; crop carousels by 40% to imply more content, the illusion of completeness), Common Region (containers/borders/background color > proximity + similarity, the false bottom trap). ③ Implementing visual hierarchy: color contrast (2 primary, 2 secondary, no more than 3 contrast variations), scale (3 levels, no more than 2 large elements), grouping (proximity + common region), the Squint Test; grids (Columns: 12 on desktop, 4 on mobile; Gutters; Margins; 8px grid; column grid/modular grid/hierarchical grid; 1128px 12-column layout with 72px column width and 24px gutter); golden ratio φ≈1.618 (applied to font size/line height/image cropping/two-column layouts). ④ Typography: 30+ entry glossary (baseline/x-height/kerning/leading/ligatures/widows), 6 typeface categories for pairing (serif/sans-serif/slab serif/script/decorative/monospace) plus pairing decorative typefaces with neutral ones, using multiple weights of a single typeface, optimal reading typefaces (352 participants tested 16 typefaces; the fastest was 35% faster than the slowest; reading speed drops 1.5 WPM per year, a 11% decline over 20 years; Garamond was suitable for only 48% of readers; there is no universal best typeface). ⑤ Color (primary/secondary/tertiary colors on the color wheel, 5 harmony schemes, 60-30-10 rule, limit to 3 colors, color meanings are not globally universal). ⑥ Imagery (Picture-Superiority Effect; photos should carry information rather than serve as decoration; 4 types of imagery; lists using color + icons are 37% faster to process than plain text; visual signifiers). ⑦ Aesthetic-usability effect (attractive designs are perceived as easier to use; 1995 Kurosu study of 26 ATMs; it masks minor issues but cannot rescue major flaws, and interferes with usability testing). Intended audience: product managers; terms are explained in industry language, content is decision-oriented (when to use/how to choose/counterexamples), all numeric values are retained.

Visual designTypesettingColor theoryEnglish edition
Product Design & UX / Other Product, Design and Learning Materials

Sajid Code UI Design in Practice (Copy Great Work > Originality / Typography Accounts for 80% of UI / Spacing and Color Selection Methods / Fixing Boring UI)

Distilled notes from Sajid's UI video tutorial (from the Will's Design Notes series), covering 7 topics across 8 sections: ① Only newbies obsess over building beautiful websites (design = solving problems, not art; check top sites on Semrush, they are all simple or even boring; five pillars = layout/typography/color/images/content) ② Originality is overrated (flat design/skeuomorphism/hamburger menu/pull-to-refresh/like button/Google/Facebook/Uber/Airbnb are all remixes; innovation lies in execution, not first invention) ③ Typography accounts for 80% of UI (remove typography styling and the interface falls apart; you only need 3 font sizes + font weights + 3 levels of lightness; use em for line-height to get natural breathing room) ④ Five rules for designing top-tier websites (design less/law of similarity and law of proximity/add more spacing then remove it/design systems/hierarchy is everything) ⑤ Fix boring UI (layer same-hue colors with different lightness + shadows; this gives the highest return from ordinary to good) ⑥ Spacing selection method (anchor font size with rem, tight inside groups and loose outside groups, button vertical padding < horizontal padding, reduce from large values downward) ⑦ HSL color palette (only adjust L lightness to create harmonious color scales; light comes from above so top is bright and bottom is dark; dark mode uses 3 lightness layers at 0/5/10%) ⑧ Motion Contract for web animation (translate perceptual motion effects into 6-dimensional parameterized constraints to feed to AI/developers). Sajid's unique arguments that distinguish him from Refactoring UI: three core mantras of 'function > beauty', 'copy mature work > originality', 'typography accounts for 80%' + treating UI as a minimal variable system (4 typography variables + 3 gray scales are enough) + the Motion Contract motion delivery method. Target readers: PMs making prototypes; jargon is explained in-industry, each section comes with Why + numerical values + do/don't. Division of labor with refactoring-ui: that article is a full handbook of 50+ tips, this article highlights Sajid's core mantras and positions plus his two exclusive tricks of motion/lightness layering; overlapping details on spacing/color/typography point to refactoring-ui and are not rewritten.

UI DesignTypesettingVisual hierarchyEnglish edition