YouTube

One-line summary: The video platform whose recommendation system (homepage + Up Next) is the contrast case for a user-owned interest graph.

What it is

A Google video host whose recommendations, per its own 2021 engineering post, drive a significant share of viewership — more than subscriptions or search. From 2026-08-21-autoresearch-user-owned-interest-graph-youtube-recs.

Why it matters to interest-graph-recs

This thread asks whether a user-drawn interest graph can produce more centered recs than YouTube’s default feed. YouTube is the only entertainment app in scope.

Key facts

Official rec surfaces: homepage and Up Next ([YouTube Blog], via 2026-08-21-autoresearch-user-owned-interest-graph-youtube-recs).
Homepage primarily uses watch history; Up Next primarily uses the video currently playing ([YouTube Help], via the same source).
Data API: watch history is watchHistoryNotAccessible; default search.list bucket is 100 calls/day (same source).
Developer Policies forbid using the API as a substitute for YouTube Applications or recreating browse without “significant independent value” (same source; re-fetched in 2026-08-21-autoresearch-best-architecture-for-a-rec-system-web-app).
Official App Engine samples: keyword discovery uses search.list; a channel’s uploads use playlistItems.list on relatedPlaylists.uploads. OAuth for private data; API key for public metadata. From 2026-08-21-autoresearch-best-architecture-for-a-rec-system-web-app.
Efstratiou (IMC 2025): official Search endpoint returns highly variable results; historical samples are hard. From 2026-08-21-academic-research-user-owned-interest-graphs-vs-platform-recs.
Liu et al. (PNAS 2025) experimentally manipulated real YouTube recommendations in a YouTube-like interface; outcome was policy attitudes, not a user-owned graph. From the same academic source.

YouTube

YouTube

What it is

Why it matters to interest-graph-recs

Key facts

Open questions

Sources

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