Connor spotted a Missouri redistricting story labelled ohio-state-politics.
Measuring showed that was not an isolated slip: 66% of the winners of a
place-based block named no place at all. Glastonbury, Anthony Albanese and a
Tim Montgomerie story were all scoring as italy-mexico; a singing-apraxia story
was ohio-state-politics.
Embeddings model meaning well and named entities poorly -- "Italian politics"
and "Australian politics" are nearly the same vector. Place is identity, not
meaning, so it is matched lexically, which is the same division of labour that
makes lexical comparison right for syndication detection and wrong for
clustering. Blocks carry `requires_any`; a block cannot win for an item whose
text names none of its terms.
Word boundaries, not substrings: "rome" is inside "chrome" and "mali" inside
"normalise". That is the trap the old blocklist fell into with "nfl" inside
"conflict".
The first implementation was wrong in a way worth recording, because it looked
correct and measured almost unchanged (66% -> 30%). It wrote a sentinel into the
RAW score before normalisation -- but when most items are gated, that sentinel
becomes the block's own mean, so a gated item z-scored to roughly zero and could
still win. Normalisation erased the gate. Applied after normalisation instead:
66% -> 0%, and place-block winners fell from 140 to 10, so 130 items now land in
the block they actually belong to.
Following Connor's point that corpus prevalence reflects how much an outlet
publishes rather than what deserves a notification: allocation should track
stated weights, not corpus composition in EITHER direction. Penalising a topic
for being prevalent is a bug; rewarding it would just amplify whoever publishes
most. This rules out the "reserve slots proportional to corpus share" model that
the previous commit's findings were pointing toward.
Two fixes:
1. Normalisation moves from per-block to per-GROUP. Taking the max across blocks
gives a subject one draw per block, so foreign affairs -- six of 23 blocks --
beat everything else by having more chances. It held 70% of the digest while
software-systems, a quarter of the corpus, held none. Collapsing to the group
before normalising prices that in. Digest conflict share 13 -> 9, space 2 ->
4, and us-national appears at all.
2. The per-group quota now keys on the INTEREST group for both lanes. Importance
blocks describe a kind of importance, not a subject, so two stories on one
subject could each take a slot via different importance blocks -- which is
what happened: both importance alerts were Middle East, one via
war-escalation and one via economic-break.
Interest alerts went from five-of-five Middle East to Ohio redistricting,
political theory and tech policy.
Also demoted prerelease/nightly build entries. The first alert software-systems
ever won was "Nvim development (prerelease) build", which matches the block
correctly and is worthless as a notification.
Documented that switching normalizer requires re-tuning [routing] thresholds:
they are in z-score units, and leaving them at 2.0 under "top-anchored"
silences the interest lane entirely.
Connor noticed 5 of 5 alerts were Middle East. Measuring showed that was not
proportionate: Middle East blocks are ~11% of the eligible corpus while
software-systems alone is 25%, yet Middle East took 35% of the top 20 and
software took none.
Two mechanisms, both measured:
1. Five conflict-* blocks could each claim their own alert slot. Interest blocks
now carry a `group`, and routing enforces max_alerts_per_group_per_day, so
related blocks share one quota. This alone moved the mix from 5/5 Middle East
to three distinct groups.
2. Z-scoring subtracts each block's MEAN, which silently encodes how much of the
corpus that block matches. software-systems has the HIGHEST mean raw
similarity of any block (0.537) and the LOWEST max z (2.51);
conflict-mideast-israel has a lower mean (0.460) and reaches 3.47. A topic is
penalised for being well covered in your own feed list.
Added `normalize = "top-anchored"` as an alternative that rescales each block by
its own upper tail instead of its mean, leaving `weight` to express preference
rather than corpus composition.
Also ruled out a plausible-sounding cause rather than assuming it: HN and
Lobsters items are title-only and much shorter than news articles, so terse
titles seemed likely to match prose probes poorly. Measured the opposite --
title-only HN items score 0.618 against the software block, ABOVE Phoronix/LWN
with summaries (0.610) and Ars Technica (0.540). Short text is not the problem;
prevalence is.
Scoring (news/score.py): every profile block is embedded and compared by
z-score WITHIN block, then weighted. Veto fires on absolute similarity OR a
margin over the interest signal; demotes apply a penalty instead of excluding,
because those categories sit adjacent to real interests.
Importance is deliberately NOT corroboration count -- the old system's error,
which measured the subscription list rather than the news. It combines block
similarity, corroboration, burst velocity, editorial prominence and aggregator
score, all weighted from config.
Routing (news/route.py): two lanes with separate budgets. Interest never
overrides quiet hours; importance may, within a hard nightly cap. Vetoes are
absolute on BOTH lanes -- the v0.2 bypass lane never consulted relevance, so a
blocklisted item could still fire at priority 5, and a test now asserts it
cannot. Budgets are spent strongest-first rather than first-come.
Measured on 1,318 real clusters: 2.5 notifications/day and a 14-item digest,
inside the 2-5/day target.
Three defects the real data exposed, none of which unit tests would have caught:
- velocity was computed as origins/hours with a 0.5h floor, giving every
SINGLE-source cluster a spurious velocity of 2.0. Growth rate is undefined
for a cluster that has not grown; it is now zero below two origins.
- deferred items (quiet hours, budget exhausted, immature) settled straight
into the digest and bypassed its cap, producing 198 items/day. Everything
that misses an alert lane now competes for one ranked, capped digest.
- feeds return large archives on first fetch -- 88 Strong Towns items going back
five months, and a BBC entry titled "BBC News app" dated 2025. Those belong in
the scoring population but must never notify, so routing now has a recency
requirement.
Reading the output also found two profile gaps: recurring columns and link
round-ups ("Catching Our Eye News Roundup", "Astronomy Picture of the Day")
scored as top-ranked interest items. They are on-topic but publish on a
schedule, so they are demoted rather than vetoed and still reach the digest.
Audit found three things compiled in that shouldn't have been: the User-Agent
carried the author's domain, the cluster threshold and window were module
constants the pipeline never overrode, and the embedding model was pinned --
which blocked the one change most likely to be wanted, swapping in a
multilingual model for native-language sources.
Configuration is now three files with distinct roles: config.toml (machinery),
profile.toml (who the reader is), sources.toml (what to read). All are
relocatable via NEWS_CONFIG_DIR. news/*.py now contains no interest, place name,
feed URL, or personal identifier.
tests/test_config.py keeps it that way: it builds a configuration for an
invented reader and asserts none of the author's identity or preferences reaches
the running code. Writing it immediately found a real bug -- CONFIG_DIR was
resolved at import time, so NEWS_CONFIG_DIR silently did nothing if set after
the module was first imported. Now resolved per instantiation.
Documented the coupling that portability creates: [clustering].threshold and
[scoring].veto_absolute are cosine constants calibrated against one corpus with
one model, so changing [embedding].model invalidates both.
Second elicitation round. The significant correction is Connor's own framing:
"my actual war interest is low, but unfortunately all wars are important." The
click history looked war-heavy only because world-news feeds are war-heavy, so
geopolitics-at-weight-1.0 was reading the corpus, not the reader. Statecraft is
now its own block and armed conflict is five weighted bands (anti-imperial,
US-involved, Mideast/Israel, undercovered, general) routed mainly by importance.
New: space-aerospace at 0.95, the highest-weighted block -- Connor is an
aerospace engineer. Plus science-discovery, environment-ecology,
ohio-state-politics, left-movements, anticolonial-sovereignty, far-right-watch,
political-theory. Linux/ricing/neovim folded into software-systems.
Introduces `demote` blocks, distinct from hard vetoes, for categories adjacent to
real interests: crypto/AI hype sits next to AI regulation, culture-war outrage
next to far-right-watch, true crime next to criminal-justice policy. Hard-vetoing
those would take real stories with them -- the lesson from the Europa League
story that both a substring blocklist and a cosine threshold wrongly killed.
Sources 39 -> 56, all fetched and verified: space (SpaceNews, Spaceflight Now,
NASASpaceflight, NASA, ESA, Phys.org), Linux (Phoronix, LWN, It's FOSS,
r/unixporn), left/anticolonial (Intercept, Drop Site, Tribune, African
Arguments). Rejected on inspection: nature.rss is journal metadata ("Author
Correction: ...") and sciencedaily is a press-release mill.
Embedding stays English-only, measured rather than assumed: the same story in
Spanish and English scored 0.758 and 0.600 cosine against a random-pair p99 of
0.634, so one pair was indistinguishable from an unrelated article. Italy and
Mexico are covered by English-language sources instead.
Also fixes clustering performance: centroids are held in memory across a batch
instead of one SELECT plus a numpy rebuild per item, which had taken ~15 minutes
for 1,258 items.
Pipeline: fetch -> normalise -> embed (CPU) -> cluster. `news poll` runs a
cycle; `news sources` and `news clusters` inspect the result. Replay and the
live service share run_cycle so tuning and production cannot diverge -- the old
system's replay harness hardcoded default params and could never sweep the
thresholds it existed to tune.
Calibrated, not guessed:
- Cluster threshold 0.82, from reading real output. 0.70 merged "Solheim Cup
capsules" with "FIBA Women's World Cup Glance"; 0.82 gives clean groups (76
items on the AfD Saxony-Anhalt election, 27 on the Nepal tunnel rescue). The
old system produced 515 clusters of which 514 were singletons.
- Corroboration counts DISTINCT buckets, not feeds, so ten outlets reprinting
one wire story is one confirmation rather than ten.
Removed after measurement: a SimHash near-duplicate stage. It gave +1.2 bits of
separation on titles and -0.2 with summaries -- news duplicates are paraphrases,
which is the same lexical trap that sank the old Jaccard clustering.
Sources: all 39 fetched against the live web, not assumed. Dropped CBC (every
feed URL times out from this host) and Tech Policy Press (serves HTML at every
documented feed path). Fixed WVXU (index.rss is an empty stub; local-news.rss
works). Reddit moved to .rss because .json now 403s without OAuth, and its
intervals raised because it 429s after three quick requests. Deutsche Welle is
back: it ships RSS 1.0/RDF, which feedparser reads and the old hand-rolled
quick-xml parser could not.
Ground-up replacement for news_triage, whose signal quality failed because it
had no representation of what its user likes -- three keywords fed to BM25 plus
a two-term substring blocklist.
profile/ holds the taste model as prose and TOML: 11 interest blocks, 3 veto
blocks, 5 importance blocks, each a set of probe sentences to be embedded.
The [scoring] constants are fitted, not guessed. CALIBRATION.md records the
measurements against all 3,885 items in the v0.2 database and 40 real feedback
labels, including two findings that changed the design:
- compare blocks by z-score within block, never raw cosine; raw cosine let
geopolitics win 78% of items and buried known-liked items at median rank 1246
of 3885 (293 after normalizing)
- veto needs a margin over the interest signal, not a threshold; a plain 0.55
cutoff falsely killed "Belgian mayor blocks club from hosting Israeli opponent
in Europa League", which the old substring blocklist also killed
connor