Atlas Index
Assisted indexing for audiovisual collections
NLP first pass + controlled vocab + HITL queue: zero publish without validation

Institutional audiovisual platform
Context
For a platform distributing academic and cultural content, pure manual indexing no longer scaled. We designed an assist service: the system proposes normalized metadata from transcripts and domain vocabularies. Humans remain the only decision-makers before catalogue publish.
Challenge
Rising volume, uneven indexing, weak discoverability. Design goal: cut first-pass time without auto-publishing vocabulary errors (people, topics, rights).
Solution
Ingest (existing transcripts or ASR) → NER/topics/embeddings → controlled-list alignment → per-field scores → keyboard HITL queue → publish API only after validation → accept/reject logs to retune thresholds and prompts.
Baseline
Without assist: 100% manual indexing, time varies by item type, backlog growing faster than editorial capacity. The useful metric is not NLP latency alone; it is median minutes to a reviewable record.
Results
- Suggestions with per-field confidence scores
- No metadata published without human validation
- Reusable OpenAPI for CMS / player
- Learning loop from accepts and rejects (thresholds, not necessarily day-one fine-tune)
Architecture decisions
Choice: Specialized extractors + LLM for normalization
Why: Reproducibility and cost at volume; the LLM does not own the whole pipeline.
Rejected: End-to-end LLM only (cost, non-determinism, weak vocabulary control)
Choice: Alignment to controlled lists
Why: Catalogue interop and editorial quality; free-text tags rot search.
Choice: Mandatory HITL before publish
Why: False positives on people/topics/rights = reputation risk and catalogue debt.
Rejected: Auto-publish above a single global threshold
Limits
- Short-text NLP latency is not end-to-end time (ASR, HITL queue, review).
- Multi-language, diarization and slide OCR stay hard cases: isolate them in the backlog.
- Without a clean vocabulary, AI accelerates chaos: start with list inventory.
Checklist to rebuild this
- Inventory vocabularies (people, topics, rights) and current record quality
- Measure baseline: median minutes / item on 50-100 samples
- Pick 1 content type for the POC (not the whole collection)
- Define metadata schema and scored fields
- Build the HITL queue before any fine-tune
- Log accept/reject per field
- Keep publish API separate from suggestion
- Per-field thresholds + dual-review policy


