Digest · week 2026-W38

The week, counted.

This week's reading

13 endpoints showed a confirmed serving divergence this occasion. No material behavioral change was confirmed by the weekly battery.

100 canary checks run (88 matched baseline) · 5000 battery trials across 20 seats · 954 stances held · 0 seats not measured. Pre-series · generated 2026-09-18

A change in when this reading is taken

The weekly series changed when it is measured. Until 30 August 2026 the weekly battery was taken on Monday morning. From that date it is taken on the Sunday night that ends the week it is labelled with. The reading is the same measurement of the same items on the same roster; only the instant it is taken has moved, by about 32 hours. This bureau has not measured whether the time a reading is taken affects a stance reading, so week-over-week comparisons that straddle this date are not treated as evidence of change, and no correction has been applied because none is known to be needed.

THE TRANSITION ALSO COST A READING. The old schedule's next run was removed nine hours before it would have fired and the new schedule's first slot had already passed, so no battery was taken in that week and none has been manufactured since. The readings either side of the change are 12.88 days apart rather than about seven. Their week labels are consecutive because a label names when a reading was taken, so the labels alone will not show you this and the interval is published beside them for that reason.

Canary checks
88of 100 match
Battery trials
5000
Stances held
954
Material behavioral changes
0battery-confirmed

Actions this occasion

one state per seat, silence quantified
2026-09-19 0 of 20 retained baseline behavior; 13 showed a confirmed serving divergence, 7 flagged a possible serving change.

Two different things are watched here. Serving checks (daily) ask whether the endpoint you call is still the build we baselined. Behavioral measurements (weekly) ask whether its positions moved. Only a battery-confirmed, published result is a material behavioral change. In the pre-series period there are zero of those, by design.

Serving divergence confirmed anthropic-a ›
CUSUM 43.75 of 2.0 alarm
4 items moved1 serving check diverged
Possible serving change openai-a ›
Δ stance 0.60 on 1–5
1 item moved
Serving divergence confirmed xai-a ›
CUSUM 0.00 of 2.0 alarm
4 items moved
Serving divergence confirmed deepseek-a ›
CUSUM 3.17 of 2.0 alarm
4 items moved
Possible serving change anthropic-b ›
Δ stance 0.40 on 1–5
Possible serving change anthropic-c ›
Δ stance 0.80 on 1–5
2 items moved
Serving divergence confirmed anthropic-d ›
CUSUM 15.50 of 2.0 alarm
2 items moved2 serving checks diverged
Possible serving change anthropic-e ›
Δ stance 1.20 on 1–5
1 item moved
Possible serving change openai-b ›
Δ stance 1.00 on 1–5
3 items moved
Possible serving change openai-c ›
Δ stance 0.80 on 1–5
2 items moved
Serving divergence confirmed google-b ›
CUSUM 18.75 of 2.0 alarm
1 item moved2 serving checks diverged
Possible serving change deepseek-b ›
Δ stance 3.00 on 1–5
10 items moved
Serving divergence confirmed openweight-a ›
CUSUM 32.25 of 2.0 alarm
5 items moved1 serving check diverged
Serving divergence confirmed openweight-b ›
CUSUM 27.50 of 2.0 alarm
9 items moved1 serving check diverged
Serving divergence confirmed openweight-c ›
CUSUM 25.50 of 2.0 alarm
6 items moved
Serving divergence confirmed openweight-d ›
CUSUM 21.00 of 2.0 alarm
11 items moved1 serving check diverged
Serving divergence confirmed openweight-e ›
CUSUM 31.50 of 2.0 alarm
6 items moved1 serving check diverged
Serving divergence confirmed openweight-f ›
CUSUM 31.50 of 2.0 alarm
1 serving check diverged
Serving divergence confirmed openweight-g ›
CUSUM 10.50 of 2.0 alarm
4 items moved1 serving check diverged
Serving divergence confirmed simulant-a ›
CUSUM 45.75 of 2.0 alarm
1 serving check diverged

Not measured: google-a, google-c, google-d, xai-b.

One state per seat per occasion, in the daily serving-check vocabulary. A baseline behavior retained seat ships its no-change e-value and the smallest shift this occasion could detect (n and power pre-registered); a new serving baseline means the served build changed and comparisons reset. A material behavioral change is only ever declared by the weekly battery, never by a daily serving check. actions.json · how states are decided

Reading the quiet

Nothing moved past the pre-registered thresholds this week, and that sentence is the product. A change-alert service earns the right to be believed on its loud days by publishing its quiet ones: same cadence, same thresholds, same evidence trail, week after week. When a change does confirm, it appears here, on the changelog, and as a diff card with the full evidence bundle.

Pre-series note: this digest counts pipeline activity while the instrument is still measuring itself; no findings publish until methodology v1.0 freezes.

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Cite this Permalink https://modelometer.com/digest · Run hash d359989e1adcb12631b37545a515ecb07b83c690ce285381390d91accda6c437 · Retrieved 2026-09-18 · week 2026-W38: the weekly battery confirmed no material behavioral changes across 5000 trials (pre-series).