llm-ingestion-okf/docs/2026-09-07-k2-pptx-odt-rtf-fixtures.md

K2 for pptx/odt/rtf on a synthetic denominator, N = 3, 2026-09-07

Order 20260906T220349Z-652851369-from-.claude. Closes the gap the previous report opened rather than filled: docs/2026-09-04-k2-pptx-odt-rtf.md measured the corpus denominator for these three office rows and found it zero — ~/corpora/okf-telling-20260829/K2/trinn1 holds 43 files and not one is a pptx, an odt or an rtf, with a known-positive control (docx → 5/5) proving the query could find. So K2 for those rows was unmeasured, which is a different fact from passes, and the corpus could not be made to say otherwise.

This report measures them on a synthetic denominator instead: three documents written here, with a hand count committed before the measurement ran. That is a weaker instrument than a corpus and the limits are stated in full at the bottom. It is not weaker than nothing, which is what the row had.

Nothing in ~/corpora/ was read or written. N there is still 43.

What was measured, and against what

tools/okf_fidelity.py asks the source document's own two questions:

• coverage — of the strings the FILE stores, how many appear in the converted text. Read from the package's own XML (or, for RTF, from the stream), never from a converter's output: a fasit derived from one converter would score that converter on its own homework.
• pairing — of the rows carrying a label and a value, how many keep both on one output line. That is the criterion a requirement table is read by.

The fixture set is tests/fixtures/k2-office/: one authored document laid out three times, in three containers, so the container and its reader are the only variable between the three measurements. A title, an intro, a 20-row label/value table, a caption, and a 4×4 grid. Norwegian throughout, with the diacritics the pipeline has to survive.

The fasit was hand-counted from the authored content and committed first, in a7b050b, before any of the numbers below existed:

	count	how it was counted
cells	56	20 rows × 2 columns + 4 rows × 4 columns
pairs	20	the 20 label rows; every label ends in a colon
distinct strings	59	title + intro + caption + 56 cells, all distinct after normalisation

The instrument derives its own denominator from each file's XML or stream, independently of that hand count. The two agree on all three documents: 59 strings, 20 pairable. A disagreement would have been the report; there isn't one.

The result

Converter: the vendored pandoc 3.9, resolved by path and version-asserted by src/llm_ingestion_okf/_pandoc.py, with -t markdown --eol=lf --wrap=none. "Product" is the text scored off the persisted concept in the bundle — the artifact Door B actually writes, not an intermediate.

format	coverage	paired	denominator
pptx	59/59 (100 %)	20/20 (100 %)	59 strings, 20 pairs
odt	59/59 (100 %)	20/20 (100 %)	59 strings, 20 pairs
rtf	59/59 (100 %)	20/20 (100 %)	59 strings, 20 pairs

Standalone (converter alone) and product (through extract_text, and through the written concept) are equal for all three — no fall from one to the other, so there is nothing here to attribute to this library.

There is no sub-100 % cell to explain. The order asks that every fall below 100 % be named with a cause; there are none, and that absence is a result about a document set we wrote, not about the format.

Door B, product path, N = 3: process_inbox over the fixture directory persisted 3/3, with 0 quarantined, 0 rejected, 0 failed and 0 skipped. K1b: 3 + 0 = 3 = N.

The negative control

100 % means nothing from an instrument that cannot see a loss. Removing one label and its value from each converted text, and re-scoring the same shipped fixtures:

format	coverage	paired
pptx	57/59 (96.6 %)	19/20 (95.0 %)
odt	57/59 (96.6 %)	19/20 (95.0 %)
rtf	57/59 (96.6 %)	19/20 (95.0 %)

The instrument moves by exactly the two strings and the one pair that were taken away. tests/test_fidelity.py carries the same control per reader as a test, so it cannot rot.

Converter version

The order asks for a comparison against the host's newer converter if the numbers fell. They did not, and the comparison was run anyway because it is cheap and it bounds a different risk: pandoc 3.9 and the host's pandoc 3.10.2 produce byte-identical output for all three fixtures (cmp, three files, no differences). These numbers are therefore not sitting on a version-fragile edge.

Two converter findings, neither of them fixed

Both were measured while laying the RTF out, both are structurally plausible input read silently wrong, and both come back exit code 0 with no warning — the same shape as the missing word/styles.xml and the inlineStr xlsx already recorded in tests/fixtures/README.md. Per the order they are reported, not patched; nothing in src/ works around either.

1. RTF cell paragraphs need \pard\intbl. Without it, consecutive \trowd…\row rows are read as each row NESTED inside the previous one. Five label/value rows came back as five levels of nested table — 2076 characters where 117 were expected. The fixture writes \intbl, which is correct RTF; a document that omits it is not this library's problem to fix, but it is a shape a real drop directory can contain.

2. The \uN? unicode escape loses the character after it. This is the form Word emits, so it is the common case rather than an edge one. Measured directly against the vendored 3.9:

A\u248?BC    ->  AøC      the ring letter arrives, the B is GONE
A\u248?xBC   ->  AøBC     the same rule seen from the other side
A\u248 ?BC   ->  AøBC     an explicit delimiter, and the text survives

The ? is taken as the control word's delimiter, and \uc1 then skips a real character. \uc0 does not change it. The fixture is written in the form that round-trips (\uN ?), so this finding is recorded here rather than baked invisibly into a fixture.

What this means for a real rtf drop. Any Word-produced RTF containing Norwegian letters will lose one character after each of them, silently. That is a defect in the converter, not in this library, and it is now a named limit of the rtf row rather than an unknown.

Honesty limits

Read these as part of the table, not as a footnote to it.

• Synthetic, N = 3, one house style. Three documents we wrote are not a corpus. They are internally consistent by construction: one author, one layout convention, one set of table shapes. A real pptx deck with text boxes over images, an odt with tracked changes, or an RTF from a different producer are all outside what was measured.
• We authored the fixtures to be readable, and they read. The 100 % says the path works end to end on documents built to exercise it. It does not say the format is covered. extract._EVIDENCE therefore still reads unmeasured for all three rows, and tests/test_k2_office_fixtures.py asserts that it does — so a later reader cannot mistake this report for promotion.
• The rtf row is the weakest of the three. For pptx and odt the fasit is read out of a package format that neither we nor the converter defined. For rtf there is no part to read, so the fasit comes from a reader written here against a stream written here. Both halves are ours, and the independence the other two rows have is missing.
• Drawn content is out of scope entirely. Conversion recovers text; a figure, a diagram or a drawn shape has no text to recover, only a caption. Every office extraction already warns about this on every call. The fixtures contain no drawn content, so this report measures nothing about it.
• pptx speaker notes, odt footnotes and RTF headers/footers carry text in real documents and appear in none of these fixtures. Unmeasured, and named here so the gap has a denominator of its own.

What changed in the tree

• tests/fixtures/k2-office/ — the three documents, hand-laid by tests/fixtures/make_k2_office.py. No converter wrote any of them: a file written by the converter and read by the converter proves only that the converter agrees with itself. The commissioning order offered pandoc as one generator option; the committed fixture policy in tests/fixtures/README.md forbids it, and the policy wins.
• tests/fixtures/k2-office-fasit.json — the hand count, committed first.
• tests/test_k2_office_fixtures.py — pins N = 3, 3/3 through Door B offline, the concept contents, the fasit, and that the rows stay unmeasured.
• tools/okf_fidelity.py — source-string readers for pptx, odt and rtf. Stated plainly because it sits outside the order's enumerated fence: the instrument the order names refused all three types (ValueError: no source-string reader for '.pptx'), so step 2 could not run without it. It is the measuring instrument, not extraction code — src/llm_ingestion_okf/extract.py is untouched, and so is every _EVIDENCE row.

Suite: 1141 passed (1127 before this work, 1132 after the fixture commit, 1141 with the reader tests). ruff check, ruff format --check and mypy --strict src/ tools/ (25 files) clean, all measured after git add. Re-running make_k2_office.py leaves git diff --quiet clean on tests/fixtures/k2-office, so the three documents are reproducible from that one file. Nothing pushed.