Similarity

This entry has no interactive specimen yet; the illustration is an editorial sketch, and product use still requires verifying semantic grouping and accessibility annotations.

{
  "evidenceType": "A design interpretation of a perceptual principle",
  "limit": "This entry does not measure the grouping strength of each attribute or prescribe specific color or size values."
}

{
  "id": "similarity",
  "type": "principle",
  "name": {
    "zh": "相似律",
    "en": "Similarity"
  },
  "aliases": [
    "Gestalt Similarity",
    "Law of Similarity",
    "相似原则",
    "相似性原则"
  ],
  "granularity": "component",
  "intents": [
    "organize-content",
    "reduce-complexity"
  ],
  "tags": [
    "grouping",
    "visual attributes",
    "Gestalt",
    "consistency",
    "visual relationships"
  ],
  "definition": "Elements that share visual characteristics such as color, shape, or size tend to be perceived as a related group, even when they are not positioned next to each other.",
  "boundary": "Similarity groups by visual attributes, not by distance. It is often overpowered by proximity or common region, and it does not replace semantic labels, headings, or accessible grouping information.",
  "signature": [
    "Elements of the same kind share color, shape, or size",
    "Elements of different kinds differ clearly in at least one attribute",
    "An element that breaks the similarity becomes a focal point"
  ],
  "when": [
    "Actions or content of the same kind are spread across locations and need a cross-region relationship",
    "Links, buttons, tags, or other same-function elements should be recognizable at a glance",
    "A single key action needs emphasis through deliberate difference"
  ],
  "when_not": [
    "Using the same styling to suggest a functional relationship that does not exist",
    "Applying the interactive color to non-interactive decorative elements",
    "Distinguishing groups by color alone without a second cue such as shape or text"
  ],
  "tradeoff": "Visual consistency conveys relationships across locations, but excessive similarity makes unrelated elements read as one group and weakens elements that need emphasis.",
  "comparison": {
    "focus": "Which elements belong to the same function or category",
    "mechanism": "Shared visual attributes influence perceived grouping",
    "cost": "Requires a consistently maintained attribute system and backup cues for color"
  },
  "sources": [
    {
      "id": "nng-similarity",
      "title": "NN/g · Similarity Principle in Visual Design",
      "url": "https://www.nngroup.com/articles/gestalt-similarity/",
      "claim": "Elements sharing visual characteristics are perceived as more related; color, shape, and size are the main similarity cues, and similarity is often overpowered by proximity or common region.",
      "checkedAt": "2026-09-15",
      "archive": {
        "lookupUrl": "https://web.archive.org/web/20260915*/https://www.nngroup.com/articles/gestalt-similarity/",
        "status": "available",
        "checkedAt": "2026-09-15T18:16:37.904Z",
        "jobId": "spn2-86531ce9f6d3d10485b70771380897121c6bc99c",
        "url": "https://web.archive.org/web/20260915181904/https://www.nngroup.com/articles/gestalt-similarity/",
        "timestamp": "20260915181904"
      }
    },
    {
      "id": "ixdf-gestalt",
      "title": "IxDF · What are the Gestalt Principles?",
      "url": "https://ixdf.org/literature/topics/gestalt-principles",
      "claim": "Elements that share superficial characteristics (shape, color, size) are perceived as grouped; similarity can be deliberately broken to emphasize a call to action.",
      "checkedAt": "2026-09-15",
      "archive": {
        "lookupUrl": "https://web.archive.org/web/20260915*/https://ixdf.org/literature/topics/gestalt-principles",
        "status": "unconfirmed",
        "checkedAt": "2026-09-15T18:06:59.312Z",
        "error": "status-request-failed",
        "jobId": "spn2-73fe8a649c9ddc92338f9f7177e4ee0255676b89"
      }
    },
    {
      "id": "smashing-gestalt",
      "title": "Smashing Magazine · Design Principles: Visual Perception And The Principles Of Gestalt",
      "url": "https://www.smashingmagazine.com/2014/03/design-principles-visual-perception-and-the-principles-of-gestalt/",
      "claim": "Similarity characteristics include color, shape, size, and texture; dissimilarity can serve as a focal point for emphasis.",
      "checkedAt": "2026-09-15",
      "archive": {
        "lookupUrl": "https://web.archive.org/web/20260915*/https://www.smashingmagazine.com/2014/03/design-principles-visual-perception-and-the-principles-of-gestalt/",
        "status": "available",
        "checkedAt": "2026-09-15T18:07:23.177Z",
        "jobId": "spn2-6a63687ff50fcbb4c132638ee0b4c05237b75c63",
        "url": "https://web.archive.org/web/20260915180846/https://www.smashingmagazine.com/2014/03/design-principles-visual-perception-and-the-principles-of-gestalt/",
        "timestamp": "20260915180846"
      }
    }
  ],
  "relations": [
    {
      "target": "proximity",
      "kind": "related",
      "condition": "Using both distance and visual attributes to express grouping",
      "reason": "Proximity relies on distance while similarity relies on shared attributes; when they conflict, distance usually wins, so the cues should agree.",
      "basis": "editorial"
    },
    {
      "target": "swiss",
      "kind": "composes_with",
      "condition": "A typographic system uses consistent sizes and colors to express hierarchy",
      "reason": "Consistent text styling lets same-level content be recognized across pages.",
      "basis": "editorial"
    },
    {
      "target": "inclusive-design",
      "kind": "informs",
      "condition": "Grouping cues depend on color",
      "reason": "Color similarity can fail for people with color vision differences and needs a shape or text backup.",
      "basis": "editorial"
    }
  ],
  "rules": [
    {
      "when": "Using color to express grouping or interactivity",
      "instruction": "Do not rely on color alone; provide a second cue such as shape, an icon, or text.",
      "strength": "must",
      "basis": "editorial"
    },
    {
      "when": "Defining styles for elements with the same function",
      "instruction": "Give them consistent visual attributes, and avoid reusing that style for elements with a different function.",
      "strength": "recommend",
      "basis": "editorial"
    }
  ],
  "principle": {
    "evidenceType": "A design interpretation of a perceptual principle",
    "limit": "This entry does not measure the grouping strength of each attribute or prescribe specific color or size values."
  },
  "demo": null,
  "version": "0.1.0",
  "editorialStatus": "drafted",
  "requirements": [],
  "demoCapabilities": [],
  "implementationNote": "This entry has no interactive specimen yet; the illustration is an editorial sketch, and product use still requires verifying semantic grouping and accessibility annotations.",
  "image": {
    "src": "/images/similarity.webp",
    "alt": "An evenly spaced grid of circles and squares where elements of the same color or shape read as a group even though they are not adjacent."
  },
  "searchTerms": [
    "分组",
    "视觉属性",
    "格式塔",
    "一致性",
    "视觉关系"
  ]
}