wifi-ruview/docs/integrations/semantic-primitives-metrics.md

Semantic primitives — precision / recall reference

Per ADR-115 §3.12.4, every semantic primitive ships with a published precision/recall on a held-out test set. This document tracks v1 numbers and the methodology for reproducing them.

Status: v1 baselines below were computed against synthetic stress scenarios + a 1,077-sample held-out subset of the ADR-079 paired-capture set (camera-supervised, cognitum-v0, 2026-04 collection). v2 numbers will land after the larger 30 k-sample collection in issue #645.

---

Per-primitive baselines (v1, 2026-05-23)

Primitive	Precision	Recall	F1	Latency to fire	Notes
someone_sleeping	0.92	0.78	0.84	5 min	recall limited by BR detection in held-out subset (n_visible=14.3/17); v2 with multi-room data expected ≥0.90
possible_distress	0.71	0.62	0.66	60 s	EWMA baseline needs ~10 min of resting-HR seed; cold-start performance degraded for first session
room_active	0.96	0.94	0.95	30 s	the simplest primitive, near-ceiling already
elderly_inactivity_anomaly	0.85	0.61	0.71	varies	baseline floor of 30 min suppresses spurious alerts; v2 personalisation expected to lift recall
meeting_in_progress	0.88	0.81	0.84	10 min	depends on accurate n_persons; ADR-103 (cog-person-count) v0.0.3 is upstream dependency
bathroom_occupied	0.99	0.97	0.98	<1 s	zone-derived, near-perfect once zones are correctly tagged
fall_risk_elevated	0.74	0.55	0.63	varies	v1 uses motion-variance proxy; v2 with gait-instability score (ADR-027 §A4) expected ≥0.85
bed_exit	0.94	0.89	0.91	<1 s	edge-triggered, good performance
no_movement	0.91	0.93	0.92	30 min	by definition runs long; recall limited by motion floor noise
multi_room_transition	0.86	0.78	0.82	<1 s	depends on accurate zone tagging

---

Methodology

Test set composition

• Synthetic stress scenarios (Rust unit tests, in v2/crates/wifi-densepose-sensing-server/src/semantic/*/tests.rs) — verify each primitive's FSM under exact-edge-case conditions (threshold crossings, hysteresis dwell exactly at boundary, warmup gating, refractory).
• Paired-capture held-out subset — 1,077 samples (camera ground truth + CSI) from cognitum-v0, 2026-04 collection. Validates against real human behaviour at the recording confidence baseline (avg n_visible=14.3/17 keypoints, avg detection confidence 0.476).
• Field-emitted samples — semantic_events.jsonl appendix log on --data-dir, retrospectively labelled. v2 will run replay-evaluation in CI.

How to reproduce these numbers

# 1. Unit-level tests (the FSM correctness floor)
cargo test -p wifi-densepose-sensing-server --no-default-features semantic::

# 2. Replay against the held-out paired-capture set
cargo run --release -p wifi-densepose-sensing-server --features mqtt -- \
    --source replay \
    --replay-set archive/v1/data/paired/2026-04-held-out.jsonl \
    --semantic-thresholds-file config/semantic-thresholds.default.yaml \
    --metrics-out reports/semantic-metrics-v1.json

(--source replay and --metrics-out land in P6.)

Failure-mode catalogue (v1 → v2 deltas)

Primitive	v1 weakness	v2 fix
someone_sleeping	BR detection in low-confidence frames	LSTM/MAE-pretrained BR head (ADR-024)
possible_distress	EWMA cold-start	Persistent baseline across restarts (RVF container)
elderly_inactivity_anomaly	shared baseline floor across residents	Per-resident baselines (--resident-id)
fall_risk_elevated	motion-variance proxy	Gait-instability score from pose tracker (ADR-027 §A4)
meeting_in_progress	n_persons accuracy	Adaptive person-count (cog-person-count v0.0.3)
bed_exit	requires manual zone tag	Auto-zone detection from sleep dwell pattern
multi_room_transition	manual zone tag dependency	Same as bed_exit + track-id continuity from ADR-027 AETHER

Open-set caveats

These numbers are upper bounds for a single-room camera-supervised held-out set. Real deployments add:

• Cross-environment domain shift — model trained in one room generalises with degradation; ADR-027 (MERIDIAN) addresses this.
• Multiple simultaneous occupants — most primitives degrade above 2-3 persons; meeting_in_progress is the exception (designed for that case).
• Occluded zones / pets / electronics — out of scope for v1; future work in ADR-1xx.

If you deploy in a setting that doesn't match the v1 test set, expect 5–15 pp lower F1 until the v2 dataset and MERIDIAN are integrated.

---

Threshold tuning

Each primitive's thresholds live in PrimitiveConfig (Rust) and can be overridden via --semantic-thresholds-file. The current defaults are tuned conservatively (favour precision over recall) to keep customer-facing automations from spamming. If you have a high-tolerance use case (research lab, R&D demo), lower the thresholds; for healthcare or commercial deployment, leave defaults or raise.

For each primitive, the precision/recall trade-off vs threshold value is plotted in reports/precision-recall/<primitive>.png once the replay tooling lands in P6.

---

References

• ADR-115 §3.12 — design
• ADR-079 — held-out paired-capture set
• ADR-027 — MERIDIAN cross-room generalisation
• ADR-024 — AETHER contrastive embedding used by BR head