Methodology

1 · Detection

Every hour PULSE collects the current headlines from public Google News category feeds (World, Business, Technology, Science, Health, Sports, Entertainment). Headlines are normalized and clustered: two headlines belong to the same story when their significant-word overlap (Jaccard similarity) reaches 50%, or their character-level similarity reaches 62%. A cluster becomes a trend — and earns a permanent page — only when at least 3 independent news sources are covering it. This threshold is our quality gate: PULSE does not create pages for single-source stories.

2 · Velocity

Velocity measures how fast a story is spreading: velocity = (articles in last 6h + 0.25 × total articles) × √(distinct sources). Source diversity is weighted because ten newsrooms covering a story independently means more than one newsroom publishing ten articles. Velocity is snapshotted hourly; the charts on every page are drawn from these snapshots.

3 · Lifecycle

Each trend carries a status, recomputed hourly: rising (velocity climbing), peaking (at or near its maximum), cooling (below half of peak), and archived (no new coverage for 48 hours). Archived pages are never deleted — they become the historical record.

4 · Predictions — and self-grading

Once per day PULSE predicts, for every live trend, whether it will still be receiving coverage tomorrow (holds) or not (fades). The current heuristic: a trend holds if its velocity is within 80% of peak and at least 8 sources are on the story. The following day each prediction is graded against what actually happened, the result is stamped on the trend's page (✓ or ✗, permanently), and the global accuracy figure is updated. PULSE cannot hide a bad call.

5 · Briefs and the no-invention contract

Trend briefs are written by an AI layer operating under a strict contract: it may use only the facts present in the collected headlines. Inventing numbers, quotes, names or causes is explicitly forbidden; when headlines don't establish a fact, the brief must say so. Every brief is labeled with how it was generated. If no AI provider is available, a deterministic extractive engine builds the brief from coverage metadata alone — pages are never empty and never fabricated.

6 · Data reuse

All PULSE metrics may be cited freely with attribution to "PULSE — Trend Intelligence" and a link. Machine-readable data: https://pulse.byoviral.com/api/trends.json · AI-assistant orientation: https://pulse.byoviral.com/llms.txt.