aod-learning-accuracy-campaign

Testing & Quality

Executable, decision-gated campaign for making learned priors and likelihoods (global prior, 168 time-priors, per-sensor P(E|H) from correlation analysis, decay half-life resolution) trustworthy on real homes. Load this when a user reports "prior stuck at 0.99/0.01", "occupancy probability doesn't match reality", "false transitions", "decay clears too fast/slow", "correlation/likelihood looks wrong", or when asked to touch data/prior.py, data/analysis.py's PriorAnalyzer, db/correlation.py, or data/decay.py half-life resolution. This is the flagship operation order for the project's hardest live problem — treat it as a runbook, not background reading.

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Source SKILL.md: https://github.com/Hankanman/Area-Occupancy-Detection/blob/HEAD/.claude/skills/aod-learning-accuracy-campaign/SKILL.md

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What this covers

The end-to-end loop for diagnosing and fixing bad learned values on a real Home Assistant install: pull ground truth, hand-verify the stored math, diagnose which stage is wrong (interval detection, denominator/period selection, bucketing, likelihood estimation, or decay half-life resolution), pick a fix from a theory-obligated menu, and validate before it ever reaches main. It exists because this project has shipped the same class of bug — a denominator or comparison subtly excluding data it shouldn't — at least five times (see Phase 2 and Provenance).

When NOT to use this: for the underlying formulas themselves (sigmoid/logit math, clamps, combine_priors derivation) use bayesian-occupancy-reference. For pulling a diagnostics export or DB copy off a real install, use aod-diagnostics-and-tooling (this skill assumes you already have both, see Phase 0). For the actual PR/merge process once a fix is validated, use aod-change-control — this skill never merges anything itself. For known-closed war stories (not open investigations), use aod-failure-archaeology. For the adjacent-areas / transition-learning subsystem specifically (merged 2026-07-06, PR #454), that is out of scope here — it consumes learned priors but doesn't produce them.

Phase 0 — Ground truth harness

Goal: prove you can hand-recompute a stored learned value from raw data before you trust anything else in this campaign. If you skip this, every later phase is built on sand.

Get a real-home diagnostics export and DB copy. Use aod-diagnostics-and-tooling for the exact pull mechanics (diagnostics JSON via Settings → Devices & Services → Area Occupancy Detection → kebab menu → Download diagnostics; DB file at <config_dir>/.storage/area_occupancy.db on the source install). You need both: diagnostics gives you the claimed current values (prior.diagnostic_snapshot() per area — see custom_components/area_occupancy/diagnostics.py:215-313), the DB gives you the raw intervals to recompute from.
Hand-recompute the global prior from the DB directly (bypasses the integration's own code — this is the point):
```
sqlite3 area_occupancy.db <<'SQL'
.headers on
.mode column
SELECT area_name, prior_value, total_occupied_seconds, total_period_seconds,
       data_period_start, data_period_end,
       ROUND(total_occupied_seconds / total_period_seconds, 6) AS recomputed_ratio
FROM global_priors;
SQL
```
recomputed_ratio (clamped to [0.01, 0.99]) must equal prior_value to within 1e-6. This only catches arithmetic bugs in the stored row — it will NOT catch the #483 class of bug, where the period bounds themselves were wrong before the ratio was ever computed. For that, independently rebuild the period from occupied_intervals_cache:
```
sqlite3 area_occupancy.db <<'SQL'
SELECT area_name, MIN(start_time) AS earliest_cached, MAX(end_time) AS latest_cached,
       SUM(duration_seconds) AS total_occupied_seconds_recomputed
FROM occupied_intervals_cache
WHERE area_name = '<AREA_NAME>'
GROUP BY area_name;
SQL
```
Then compare latest_cached to global_priors.data_period_end for that area. They should be very close to "now" at analysis time — if data_period_end is stuck hours or days behind latest_cached/the current wall clock while the area has been quiet, you have re-found the #483 pattern (period truncated at last_interval_end instead of running to now). See custom_components/area_occupancy/data/analysis.py around the calculate_and_update_prior period-selection block — the correct behavior (period always ends at now, via actual_period_end = now) landed on main via PR #491, merged 2026-07-06 (fixes #483); re-verify with git show main:custom_components/area_occupancy/data/analysis.py | grep -n "actual_period_end" if you suspect a regression.

Hand-recompute one time-prior bucket. Time priors are bucketed by local wall-clock day-of-week/hour, 168 buckets per area, in custom_components/area_occupancy/db/schema.py's priors table (day_of_week, time_slot, prior_value, data_points). You need the HA instance's configured timezone (Settings → System → General → Time Zone on the source install — it is not stored per-area in the DB). Recompute bucket (dow, hour) by hand:

import sqlite3
from datetime import timedelta
from zoneinfo import ZoneInfo

TZ = ZoneInfo("<HA_INSTANCE_TIMEZONE>")   # from Settings > System > General
AREA = "<AREA_NAME>"
DOW, HOUR = 0, 8   # Monday 08:00-09:00 local, e.g.

con = sqlite3.connect("area_occupancy.db")
rows = con.execute(
    "SELECT start_time, end_time FROM occupied_intervals_cache WHERE area_name = ?",
    (AREA,),
).fetchall()

occupied = 0.0
total = 0.0
# Walk every local hour in [sample_period_start, sample_period_end) for this area/bucket
# from the `priors` table row, summing overlap with `rows` for occupied seconds
# and the full hour length for total seconds. (Mirrors calculate_time_priors in
# custom_components/area_occupancy/data/analysis.py — walk in UTC, bucket by local time,
# to stay DST-safe; see that function's docstring before you copy this loop verbatim.)

Compare your hand value (clamped to [0.03, 0.9] — TIME_PRIOR_MIN_BOUND/TIME_PRIOR_MAX_BOUND, const.py:186-187) to the stored prior_value for that (day_of_week, time_slot) row. Expected: within 1e-6.

If the stored value differs from your hand value: you found a bug in the period-selection, bucketing, or denominator logic, not a rounding artifact — branch to aod-debugging-playbook, treating it as a "#483-class" bug (systematic denominator/period truncation), and come back here once fixed to re-verify before moving to Phase 1.

Phase 1 — Baseline measurement

Define these metrics precisely before touching any code, and compute them for the specific real-home area under investigation.

Metric	Definition	How to compute	Known-good range
Prior calibration error	`\|stored global_prior − true occupancy rate over the same window\|`	True rate: from an independent reference signal (e.g. manual log, a second known-reliable presence sensor) covering the same `data_period_start`→`data_period_end` window from `global_priors`. Stored: that row's `prior_value`.	No repo-wide target exists. The one documented real case (#483, kitchen mmWave) had true rate 28–35% over 7 days while the buggy prior pinned at 0.99; after PR #491's fix the same synthetic scenario in `tests/test_data_analysis.py::test_valid_calculation_sets_correct_prior` recomputes to 0.25 for 2h occupied / 8h period. Use "does the recomputed ratio match the true rate to within a few points" as the bar, not a repo-blessed number.
False-transition count	Number of times the area's `binary_sensor.<area>_occupancy` (via `Area.occupied()`, threshold-gated at `config.threshold`, default 0.50) flips state without a corroborating flip in your chosen reference signal, over N days	Pull `occupied`/`probability` history for the binary sensor from the recorder (or replay `intervals` + `global_priors`/`priors` through the simulator, see Phase 3 fenced-path warning) and diff transition timestamps against the reference signal's transitions, with a small tolerance window (a few seconds to a couple minutes, matching `motion_timeout` — `DEFAULT_MOTION_TIMEOUT = 300s`, `const.py:132`)	No repo-wide target exists; this is a per-area empirical baseline you establish, not a constant to look up.
Sample sufficiency	Number of samples correlation analysis had for this entity	`SELECT sample_count FROM correlations WHERE area_name=? AND entity_id=?;`	Must be ≥ `MIN_CORRELATION_SAMPLES = 50` (`const.py:323`) before you trust `prob_given_true`/`prob_given_false` for that entity at all — below 50, `db/correlation.py`'s gate returns early / discounts confidence (see Phase 2).
Time-prior data density	Weeks of data feeding a given `(day_of_week, time_slot)` bucket	`SELECT data_points FROM priors WHERE area_name=? AND day_of_week=? AND time_slot=?;`	`data_points` is a diagnostic-only field — `calculate_time_priors` (`data/analysis.py:675-803`) does NOT gate on it before writing a slot's prior. A bucket with `data_points = 1` is exactly as "trusted" by the code as one with `data_points = 12`. This is a real gap — see Phase 3's min-sample-gate proposal.

Also record, for the area under investigation: config.threshold, purpose, whether it has a custom half-life override, and whether it's SLEEPING-purpose (the only purpose with an awake/sleep half-life split — see Phase 2).

Phase 2 — Diagnosis tree

Work top-down; each branch has a discriminating query so you don't have to guess.

If priors look wrong (calibration error large)

Is occupied_intervals_cache itself wrong (interval detection)?
├─ Query: SELECT * FROM occupied_intervals_cache WHERE area_name=? ORDER BY start_time DESC LIMIT 50;
│  Compare each interval's start/end against the raw `intervals` table for motion/sleep/media
│  entities in that window (get_occupied_intervals in db/queries.py merges motion+sleep+media,
│  applies motion timeout ONLY to motion intervals via apply_motion_timeout — a media-only
│  "occupied" interval never gets extended past its actual end).
│  → If cache intervals don't match raw sensor activity: bug is in
│    build_motion_query/build_presence_query/process_query_results (db/queries.py) or in
│    apply_motion_timeout/merge_overlapping_intervals (utils.py). Branch to
│    aod-debugging-playbook.
│
Is the DENOMINATOR/period wrong (the #483 bug class)?
├─ Query: compare global_priors.data_period_end to "now" at the time of the last analysis run
│  (coordinator.py's hourly analysis timer, ANALYSIS_INTERVAL=3600s, const.py:343).
│  → If data_period_end lags "now" by more than one analysis cycle while the area has valid
│    recent cache entries: this IS the #483 pattern re-emerging on a branch that predates or
│    regressed the fix. The fix itself (period always ends at `now`) is on `main` via PR #491,
│    merged 2026-07-06 — if you're seeing this on current `main`, treat it as a regression, not
│    the original bug, and re-verify with `gh pr view 491`.
│
Is the BUCKETING wrong (time priors only)?
├─ Query: pick one bucket, redo Phase 0 step 3 by hand. If the stored value only diverges for
│  buckets spanning a DST transition, check calculate_time_priors's UTC-walk logic
│  (data/analysis.py:675-803) — it's deliberately designed to walk hour-by-hour in UTC and
│  derive the local bucket key per iteration specifically to avoid DST fall-back ambiguity
│  (repeated local hours). A regression here would most likely reappear as a bucket with an
│  implausible data_points count (too high, from double-counting a repeated local hour) around
│  a DST boundary date.

If likelihoods look wrong (a sensor's contribution to probability feels off)

Confirm sample sufficiency first: sample_count >= MIN_CORRELATION_SAMPLES (50) in the correlations table for that entity — below 50, don't trust the numbers at all; db/correlation.py:99 gates the raw computation, :1056 discounts confidence as abs_correlation * (1 - 50/sample_count), and :1541 re-invalidates on reload if it ever drops back under 50.
For binary sensors (motion/door/media/appliance/etc.), likelihoods come from analyze_binary_likelihoods (db/correlation.py:324-620) — a duration-overlap method, not a point-sample method: it sums how many seconds the sensor was in an active state during occupied vs. unoccupied cache intervals, then divides. This means the same occupied_intervals_cache ground truth that feeds priors also feeds likelihoods — if you found an interval-detection bug in the priors branch above, expect corresponding likelihood distortion for every binary sensor in that area, not just the prior.
Check for the "black hole" clamp: prob_given_true/prob_given_false are clamped to [0.05, 0.95] (db/correlation.py:584-588) — a sensor at exactly 0.05 or 0.95 might be a real strong signal, or might be masking a near-0/near-1 raw ratio; check analysis_error on the correlations/entities row (no_occupied_intervals, no_active_intervals, no_active_during_occupied) before trusting the clamped number — any of those error strings means the type-default likelihood was used instead of a learned one, not the clamped value.
For numeric/environmental sensors, use scripts/visualize_distributions.py "<Area Name>" <entity_id> --db-path config/.storage/area_occupancy.db --days 30 to plot the raw histogram against the fitted Gaussian and visually confirm the learned mean/std actually fit the data, rather than trusting correlation_strength blind (this is exactly what that script is for — see its docstring).

If decay looks wrong (clears too fast/slow, or ignores a custom half-life)

Trace Decay.half_life → Decay._resolve_purpose_half_life() (custom_components/area_occupancy/data/decay.py). Only AreaPurpose.SLEEPING has an awake_half_life (620s, data/purpose.py) — every other purpose returns self._base_half_life unconditionally, so this branch only matters for Bedroom/Sleeping-purpose areas with configured sleep_start/sleep_end.
Settled bug (#481, fixed via PR #493, merged 2026-07-06): outside the configured sleep window, _resolve_purpose_half_life() used to unconditionally return self._purpose.awake_half_life (620s) even when the user had configured a custom half-life for that area — silently discarding it. The fix ("mirrors the custom-vs-default semantics established for #440") added a guard before the sleep-window check: if self._base_half_life != self._purpose.half_life: return self._base_half_life — i.e. if the configured half-life isn't the purpose's own default, the sleep/awake split never overrides it. This is live on main; re-verify with gh pr view 493 --json state,mergedAt if you suspect a regression.
If you hit this bug class again elsewhere: the general pattern (see Saga 2 in aod-failure-archaeology) is "is-this-value-a-user-override-or-a-coincidentally-matching-default" — Purpose.is_purpose_half_life() in data/purpose.py is the load-bearing comparison; it was already burned once (#439/#440) by comparing against any purpose's default instead of only the selected purpose's default. Any new decay/half-life logic must re-check which comparison it's making.
Also check Decay.modifier_factor (adjacency Phase 4 decay-stretch, only relevant if the area has adjacent-area config — merged to main via PR #454, 2026-07-06; still out of scope for a learning-accuracy investigation per this skill's "When NOT to use this" note, since it consumes decay rather than producing learned values, but it is no longer branch-gated).

Phase 3 — Solution menu (ranked, each with a derivation obligation)

Rule for every item below: predict the numeric effect on your Phase 1 baseline BEFORE writing code. If you can't state a predicted number, you don't understand the mechanism well enough to touch it yet.

#	Fix	Mechanism	Derivation obligation (predict BEFORE coding)	Risk	Test plan
1	Interval-merge / motion-timeout tuning	`apply_motion_timeout`/`merge_overlapping_intervals` (`utils.py`) control how raw motion edges become "occupied" intervals; `DEFAULT_MOTION_TIMEOUT=300s` (`const.py:132`)	For a specific area's raw motion log, hand-compute the merged interval set at the current timeout vs. a candidate timeout; state the predicted change in total occupied seconds and interval count	Changes ground truth for BOTH priors and likelihoods simultaneously (shared cache) — a "fix" here silently re-derives every downstream learned value for that area	Add a fixture with known raw motion edges + expected merged intervals at both timeouts; run `tests/test_db_correlation.py`/interval-merge tests before/after
2	Min-sample gate before trusting learned priors/likelihoods (fallback to default below threshold)	Mirror `MIN_CORRELATION_SAMPLES` (used for likelihoods) — time priors currently have NO such gate (`data_points` is diagnostic-only, Phase 1)	State the exact threshold (e.g. weeks-of-data or `data_points` count) and predict which currently-populated buckets in your real-home DB would flip to "insufficient data → use global/default prior" at that threshold	Sacred config surface risk is low (no user-facing config change needed) but changes silent behavior for every area with sparse history — could visibly change existing installs' probability on upgrade	Unit test: a bucket with `data_points` below threshold must fall back to global_prior/purpose default, not its own (possibly noisy) `prior_value`; regression test with hand-picked before/after `data_points` values at the boundary
3	Time-prior smoothing across adjacent buckets	Currently each of the 168 buckets is independent — no borrowing from neighboring hours/days	Predict the smoothed value for one sparse bucket given its neighbors (e.g. simple weighted average with 2 adjacent hours) and confirm it moves calibration error in the right direction for a real sparse bucket, not just in theory	Changes math for literally every area — this is the highest blast-radius item on this list; touches the "no silent math changes" unwritten law hardest	Full regression suite on `tests/test_data_prior.py` + `tests/test_data_analysis.py`; hand-computed expected values for at least 3 real buckets (dense, sparse, DST-boundary) before merging
4	Likelihood learning improvements from correlation data (e.g. confidence-weighted blending with type defaults instead of hard `analysis_error` fallback)	`analyze_binary_likelihoods`/`analyze_correlation` (`db/correlation.py`) currently either use a fully-learned clamped value or fully fall back to type defaults — no blend	Predict, for one real entity with borderline sample count (just above/below 50), how a confidence-weighted blend changes its effective `prob_given_true` vs. today's binary choice	Same shared-ground-truth risk as #1; also touches the `strength_multiplier`/`effective_weight` pipeline in `utils.py` which is otherwise stable	Unit tests with sample_count fixed at 49/50/51/100 boundary values; confirm blend continuity (no discontinuous jump at the threshold)
5	Purpose-floor recalibration (per-purpose `min_prior` values)	`Purpose.min_prior` table (`data/purpose.py`) currently: PASSAGEWAY=0.1, DRIVEWAY=0.05, all others=0.0 — capped below `config.threshold - PRIOR_FLOOR_THRESHOLD_MARGIN(0.01)` per issue #435	Predict which real areas' effective prior floor would change and by how much; this is the lowest-leverage item since it only ever raises the floor, never fixes a systematically wrong learned value	Lowest risk of the five (bounded, capped-below-threshold by construction) but easy to convince yourself it "fixed" a bug that was actually elsewhere — a floor change can mask a still-broken denominator	`tests/test_data_prior.py::test_min_prior_override_scenarios`-style parametrized cases; explicitly verify a genuinely-wrong learned prior still surfaces as wrong (floor doesn't hide it)

Rank order above is intentional: fix interval/denominator truth (mechanical, shared-ground-truth) before adding smoothing or blending logic on top of it — smoothing a wrong signal just gives you a smoother wrong signal.

Phase 4 — Validation and promotion

No fix from Phase 3 goes anywhere near main without all of the following, in order:

Regression tests encoding the correct math, not just "test doesn't crash." Follow the PR #491 pattern exactly: the old test (tests/test_data_analysis.py::test_valid_calculation_sets_correct_prior) had the buggy expected value (0.99) baked into its assertion; the fix corrected the assertion to the hand-derived value (0.25) and added a dedicated regression test (test_quiet_tail_included_in_denominator) that fails if the bug ever comes back. Any fix in this campaign needs the equivalent: a test whose expected value you hand-derived in Phase 0/2, not one copied from the current (possibly wrong) output.
Simulator scenario — paste a run_analysis service-response snapshot (from custom_components.area_occupancy.service.py's run_analysis action) into simulator/app.py (run via python main.py from repo root) and interactively toggle sensors to sanity-check the fix's effect end-to-end. Do not treat the simulator's own internal state machine as ground truth — it has zero test coverage of its own (simulator/ has no test_*.py files; confirmed by direct listing, only app.py/__init__.py), it's a visualization/debugging aid built on real integration code (EntityType/Entity classes imported directly), not a validated oracle.
Pre-merge DB-copy check — run the fix against the actual DB copy from Phase 0 (or a fresh sync from the source install) for at least one full analysis cycle (hourly, ANALYSIS_INTERVAL=3600s), and record before/after deltas for every Phase 1 metric on that specific area. "It looks better" is not a result; the number must move in the predicted direction from your Phase 3 derivation, by roughly the predicted amount. Note this is the pre-merge validation stage against copied data — it is distinct from, and does not replace, the post-merge live-install soak in aod-research-methodology's idea lifecycle (where the merged fix rides along in the next release on a real install before being declared done). A campaign fix goes through both, in that order.
Route through aod-change-control — this campaign's output is a diagnosed bug + a validated fix + before/after numbers. It is never merged on eyeball, and it is never merged by this skill directly.

Fenced wrong paths (do not do these)

Widening the [0.01, 0.99] clamps (MIN_PROBABILITY/MAX_PROBABILITY, MIN_PRIOR/MAX_PRIOR, const.py:173-176) to "fix" a pinned prior. The clamp isn't the bug; something upstream produced a ratio that saturated it. Widening the clamp just moves where saturation becomes visible.
Truncating the observation period to make a metric look better (this is literally the #483 bug — see Phase 2). The period must always extend to "now"; anything else drops known-unoccupied time from the denominator.
Hand-tuning constants per-home. Every threshold in this file (MIN_CORRELATION_SAMPLES, half-life defaults, TIME_PRIOR_MIN_BOUND/MAX_BOUND, etc.) is a repo-wide default. A fix that only works because you hardcoded a number for one specific install's DB is not a fix — the "config surface is sacred" unwritten law means new user-facing knobs need config-flow + migration work (see aod-config-and-flags), not silent per-home constant edits.
Trusting the simulator backend as ground truth for anything you haven't independently hand-verified per Phase 0/4 — it is untested code, not an oracle, however convenient it is to click sensors and watch numbers move.
Changing math and tests in the same breath without a hand-computed expected value first. If your only evidence a change is correct is "the test I also just wrote passes," you've encoded your assumption, not verified it. Do Phase 0/1's hand computation, THEN write the code, THEN write the test against the hand-derived number.

Provenance and maintenance

Date-stamped: 2026-07-06 (post-merge sweep, main HEAD 17b71d2), integration version still 2026.5.17 (custom_components/area_occupancy/manifest.json, pyproject.toml, const.py::DEVICE_SW_VERSION) — none of the fixes below have shipped in a tagged release yet.

Merged since the prior sweep, all confirmed on main as of 2026-07-06:

PR #491 (fix: quiet-tail global-prior denominator, fixes #483) — merged 2026-07-06; re-verify: gh pr view 491 --json state,mergedAt
PR #493 (fix: bedroom custom half-life outside sleep window, fixes #481) — merged 2026-07-06; re-verify: gh pr view 493 --json state,mergedAt
PR #454 (feat: adjacent-areas) — merged 2026-07-06; out of scope for this skill but shares the coordinator tick; re-verify: gh pr view 454 --json state,mergedAt

Re-verification commands for every volatile fact category in this skill:

Clamp/threshold constants (MIN_PROBABILITY, MIN_PRIOR, TIME_PRIOR_MIN_BOUND, MIN_CORRELATION_SAMPLES, etc.): grep -n "MIN_PROBABILITY\|MAX_PROBABILITY\|MIN_PRIOR\|MAX_PRIOR\|TIME_PRIOR_MIN_BOUND\|TIME_PRIOR_MAX_BOUND\|MIN_CORRELATION_SAMPLES\|PRIOR_FLOOR_THRESHOLD_MARGIN\|DEFAULT_MOTION_TIMEOUT" custom_components/area_occupancy/const.py
Global prior period-selection logic: grep -n "actual_period_end\|actual_period_duration" custom_components/area_occupancy/data/analysis.py
Time-prior bucketing/DST handling: read custom_components/area_occupancy/data/analysis.py's calculate_time_priors function in full (docstring + body)
Likelihood computation and clamps: grep -n "def analyze_binary_likelihoods\|clamp_probability(prob_given" custom_components/area_occupancy/db/correlation.py
Decay half-life resolution: read custom_components/area_occupancy/data/decay.py's _resolve_purpose_half_life in full; purpose defaults in custom_components/area_occupancy/data/purpose.py
PR/issue merge state for anything cited above: gh pr view <n> --json state,mergedAt,statusCheckRollup / gh issue view <n> --json state
Coverage gate: grep -n "fail_under" pyproject.toml (currently 85%, comment claims 90% — believe the number, not the comment)
Simulator test coverage: find simulator -maxdepth 1 -iname "test*" (expect no matches as of this writing)