---
configs:
  - config_name: default
    data_files:
      - split: train
        path: train.jsonl
      - split: test
        path: test.jsonl
      - split: queries
        path: test.jsonl
  - config_name: items
    data_files:
      - split: items
        path: items.jsonl
---

# MovieLens Leave-One-Out

Five chronological interactions predict the next interaction. One final test target per user; no rating filter. Histories are audit-only, not wholesale model inputs. Actors are supplementary; see actor_sources.json.

```json
{
  "schema": "movie-fields-v1",
  "source": "official MovieLens 100K",
  "sample_policy": "leave-one-out-windows",
  "past_order": "oldest-first",
  "history_length": 5,
  "stride": 1,
  "shuffle_seed": 42,
  "timestamp_policy": "rating timestamp then original u.data row ordinal; ties are not verified watch order",
  "target_policy": "immediate next interaction, any rating; final interaction held out per user",
  "catalog_items": 1682,
  "split_counts": {
    "train": 94342,
    "test": 943
  },
  "history_rows": 943,
  "seen_items_filtered": false,
  "movies_with_actors": 1618,
  "actor_join_methods": {
    "unique_official_movielens_title_year_link_imdb_year_checked": 1268,
    "unique_title_adjacent_release_year_inferred": 56,
    "unique_imdb_title_year": 268,
    "unmatched": 31,
    "explicit_imdb_id_in_original_url": 53,
    "ambiguous_title_year": 6
  },
  "source_events": 100000,
  "users": 943,
  "users_too_short": 0,
  "timestamp_ties": 50561,
  "held_out_events_in_train": 0
}
```

## Index-only plots

Samples and metadata are unchanged. Select `--recommendation-index-content metadata-plot` to index `search_text`; the default still uses metadata-only `text`. Plots never enter histories. Keep plot_source attribution and its content license when distributing. See plot_enrichment.json for coverage and byte-identical files.