{
  "title": "Where digital experiences give us a stopping point",
  "prepared": "2026-09-27",
  "kind": "Original explanatory framework and interaction model; no original behavioral measurements or numerical rankings.",
  "sources": [
    {
      "id": "youtube",
      "title": "YouTube Help: Autoplay videos",
      "url": "https://support.google.com/youtube/answer/6327615?hl=en",
      "supports": "With Autoplay on, another related video can play after the current one ends. The setting can be changed and the next video can be canceled. Used for product behavior only, not effects on time spent."
    },
    {
      "id": "pagination",
      "title": "GOV.UK Design System: Pagination",
      "url": "https://design-system.service.gov.uk/components/pagination/",
      "supports": "Navigation between content pages; advise splitting content only when it improves service performance or usability. Guidance warns of keyboard problems with infinite scroll. Not a claim that pagination always improves outcomes."
    },
    {
      "id": "confirmation",
      "title": "GOV.UK Design System: Confirmation pages",
      "url": "https://design-system.service.gov.uk/patterns/confirmation-pages/",
      "supports": "A confirmation should establish completion of a transaction and explain what happens next. The application example distinguishes submission from later confirmation of registration."
    },
    {
      "id": "w3c",
      "title": "W3C: Understanding WCAG 2.2, Pause, Stop, Hide",
      "url": "https://www.w3.org/WAI/WCAG22/Understanding/pause-stop-hide.html",
      "supports": "User control of automatically moving or updating visual information presented alongside other content, subject to the criterion's conditions and essential-content exceptions. Not a blanket prohibition of autoplay."
    }
  ],
  "matrix": [
    {
      "id": "finite-choice",
      "collection": "Known end",
      "transition": "You choose next",
      "example": "Six saved articles, opened one at a time",
      "meaning": "A boundary between items and a final item.",
      "color": "#2855cf",
      "pale": "#edf3ff",
      "symbol": "▤"
    },
    {
      "id": "finite-auto",
      "collection": "Known end",
      "transition": "Next starts automatically",
      "example": "A six-track queue, with repeat and extra recommendations off",
      "meaning": "Items can flow together even though the queue has an end.",
      "color": "#7040c7",
      "pale": "#f4efff",
      "symbol": "▶"
    },
    {
      "id": "open-choice",
      "collection": "No fixed end shown",
      "transition": "You choose next",
      "example": "An expanding catalogue with a Load more control",
      "meaning": "A choice to continue without a promise of reaching the last item.",
      "color": "#08756b",
      "pale": "#eef9f5",
      "symbol": "＋"
    },
    {
      "id": "open-auto",
      "collection": "No fixed end shown",
      "transition": "Next starts automatically",
      "example": "A stream that keeps supplying another item",
      "meaning": "A finished item is followed by another; the collection has no declared finish.",
      "color": "#b8412d",
      "pale": "#fff1eb",
      "symbol": "→"
    }
  ],
  "model": {
    "sampleItems": 6,
    "collectionOptions": [
      {
        "id": "finite",
        "label": "Six-item collection"
      },
      {
        "id": "open",
        "label": "No fixed end shown"
      }
    ],
    "transitionOptions": [
      {
        "id": "choice",
        "label": "You choose next"
      },
      {
        "id": "auto",
        "label": "Automatic next"
      }
    ],
    "limits": "A deterministic teaching model. Every step is manually triggered by the reader; no timer or actual autoplay. The open-ended case stops after six sample items for demonstration and explicitly does not call that collection completion. Changing either mode resets the sample.",
    "default": "finite-choice"
  },
  "rules": [
    {
      "target": "/spider-solitaire",
      "anchor": "Spider Solitaire",
      "boundary": "Eight complete same-suit King-to-Ace runs removed",
      "role": "A subgoal is different from the whole goal.",
      "verification": "src/engine/spider/rules.ts: isWin tests foundations.length === TOTAL_RUNS; src/engine/spider/types.ts sets TOTAL_RUNS = 8."
    },
    {
      "target": "/forty-thieves-solitaire",
      "anchor": "Forty Thieves Solitaire",
      "boundary": "All 104 cards in foundations",
      "role": "An empty stock is exhausted input, not a sufficient win or terminal-state test.",
      "verification": "src/engine/fortythieves/rules.ts: isWon sums foundations to 104; empty stock alone is not the deadlock test."
    },
    {
      "target": "/pyramid-solitaire",
      "anchor": "Pyramid Solitaire",
      "boundary": "No cards remain in the pyramid",
      "role": "Completion follows the goal, not the disappearance of every visible object.",
      "verification": "src/engine/pyramid/rules.ts and English Pyramid FAQ: pyramid.every(card => card === null). Stock/waste may remain."
    }
  ],
  "scope": "This page explains interface structure and specific rules. It does not estimate engagement, addiction, productivity, or changes in screen time. The taxonomy is editorial, not a validated psychological scale. Product documentation checked September 27, 2026."
}