Generator

What is repeated, against what survives

A generator in the who found it, and when library, called 46 times across 11 essays. Below: what it draws with nothing specified and with the settings the essays give it, what it checked while drawing, and everywhere it is used.

attestation-gap is one function. Everything below was drawn by it when the site was last published, at settings taken from the essays rather than invented for this page — so a figure here is the same figure a reader meets in an essay, and when the generator changes, this page changes with it.

With nothing specified

`view: "resample", show: "counts"`

`view: "resample", show: "chao"`

`view: "fragility", only: [recreational-folding, senbazuru, ceremonial-wrapping, pajarita, paper-japan, froebel, one-cut-star, fold-and-cut]`

What it checked while it drew

Collected while it drew, not written by hand. The count is how many separate times that claim was put to the test.

the median claim is dated 201.5 years earlier than anything that attests it ×12
8 of 15 claims are popularly dated EARLIER than the oldest surviving source for them ×10
every claim dated earlier than its own earliest evidence says why — 8 of them ×7
every entry in the record names a dated source of a stated kind — 15 checked ×7
all 4 lineages are jointly attested from 1970, and that date is 25 years from where the same claims are popularly dated together — against 400 for the worst single claim ×5
the chart carries 15 claims, each with a dated source ×5
4 claims about practice, each with a dated surviving source ×3
4 claims would have no surviving witness at all after one loss, and 2 would be reduced to one ×3
4 of 8 claims rest on exactly one surviving source — 50% of the record has a single witness ×3
8 claims, each stating how many independent sources survive for it ×3
67.1% of the resamplings return exactly 1838, against 67.2% for the chance that a draw of 5 from 5 includes one named entry — the observed value is simply the holder being drawn ×2
8 claims are dated ahead of their evidence and 4 of those have more than one witness ×2
the average overrun falls from 357 years to 193 once the single-witness claims are set aside — the phenomenon this field is about is carried by documents that have no second copy ×2
the individual claims are contested by up to 400 years, and the joint date is a maximum of two source years and therefore not contested at all ×2
the median hardly moves — 201.5 years against 184.5 — so what the losses would take is not a general tendency but the two largest cases ×2
2 of the fifteen claims could bring the statistic to 250 on their own, and the other 13 could not at any date whatever ×1
6 claims run the other way — attested before it was popularly dated ×1
a source 30 years earlier for froebel puts the joint date at 1808: the maximum falls year for year until it meets senbazuru at 1797, and not one year further ×1
a source two centuries earlier for any of the other 4 lineages leaves the joint date at 1838 — only the holder's evidence reaches it ×1
across all 105 pairs in the record the later source belongs to the better-attested claim in 46, to an equally attested one in 24 and to the worse-attested in 35 — under half, so a maximum inherits the LATER half of a pair and not the better ×1
and 5 of the fifteen raise it when they are removed, because a claim dated close to its own evidence drags a mean of large gaps down ×1
and re-reading a single entry's source count moves it by 3.2 claims, because the estimate is a ratio of two counts of five ×1
and the best any single discovery can do is take 25 years off 357, so no one document changes the picture ×1
every one of the 15 claims rests on between one and 4 surviving sources, and the counts are 5 on 1, 5 on 2, 3 on 3, 2 on 4 ×1
finding a source 200 years earlier for 4 of the fifteen claims would RAISE the statistic, not lower it — a claim dated near its own evidence leaves the mean when the evidence overtakes the claim, and the mean of what is left is larger ×1
not one of 20000 resamplings of the 5 lineages puts their joint date later than 1838, because a resample is drawn from the record and the record holds no source later than its latest ×1
of the 10 pairs of lineages, the later source belongs to the claim with FEWER surviving witnesses in 4, to the one with more in 4, and to a single witness in 4 ×1
removing one entry moves the statistic by as much as 140 years across the fifteen — from 268 without recreational-folding to 408 without froebel ×1
resampling the record puts a ninety per cent interval of 150 to 591 around a statistic quoted as 357 — the interval is wider than the number ×1
the estimator says 2.5 claims left no surviving source, with a ninety-five per cent interval from 15.4 to 30.6 against 15 observed — an interval several times the estimate ×1
the joint date rests on the later of two surviving sources, so it is as good as the better-attested of any two claims rather than as good as the worse ×1
the joint gap of 1 year is kept only while froebel is drawn; every resample that misses it jumps to between 293 and 980 years ×1
the middle gap of the whole record resamples to a ninety per cent interval of -10 to 110, which is a fifth the width the mean's interval has ×1
the seven claims about results hold 69 of the 105 pairwise joint dates, the practices 33 and paper itself 3 — a maximum over the record is a statement about the twentieth century ×1
the two counts an unseen-class estimate reads are equal — 5 claims resting on one source and 5 on two — which is the whole of what such an estimate would have to work from ×1
the two largest overruns in the whole record — Paper is folded for amusement in Japan at 980 years and The thousand cranes at 897 years — each rest on exactly one surviving document ×1

Where it is called

Every figure listed here is drawn by the same rule, so a mistake in the rule would be in all of them at once, and so would a correction.

A question the record is too small to answer

Five of the fifteen claims rest on one surviving source and five on two, and those two counts are exactly what an estimate of the claims that left no source at all is made of. Applied, it says two and a half are missing. Its ninety-five per cent interval runs from fifteen to thirty-one, re-reading a single entry's source count moves it by a fifth, and its independence assumption is false in the one way documents actually fail — which is what makes computing it worth more than declining to.

A resampled maximum can only fall

The joint date of paper folding's five lineages is 1838, and resampling the record twenty thousand times returns 1838 in two draws of three and an earlier year in the rest — never a later one. That is not firmness. It is the chance that a draw of five from five includes one named entry, and it is the reason a resampled interval cannot be put on a maximum at all. Read over all 105 pairs in the record, a joint date inherits the later half of its pair, not the better-attested one: the better in 46, the worse in 35, and a single surviving witness in 28.

Nothing here is as old as it sounds

Paper folding is described everywhere as an ancient art. The oldest surviving book of it was printed in 1797, the oldest reference to folding for amusement is from 1680, and the median claim in this subject is dated two centuries before anything that attests it.

One lost source and the story changes

Five of the record's fifteen claims rest on exactly one surviving document. Take those away and the field's most-quoted statistic — how far ahead of its evidence a popular date runs — falls from three hundred and fifty-seven years to a hundred and ninety-three, while the median hardly moves at all. The effect is not a tendency spread through the record; it is two documents, and both of them are single-witness.

Some discoveries would make it worse

The field's headline statistic averages the claims dated ahead of their evidence. So a document found for a claim that was nearly right removes a small number from a mean of large ones and the average overrun goes up: finding a source two centuries earlier for the kindergarten entry would take the figure from 357 to 408. The four claims where a discovery helps can take twenty-five years off each, and no single document at any date can bring the number to 250.

The cure was named first

A heavy-tailed search runtime, the arithmetic for cutting it off and restarting, and the reason restarts work at all were established in the study of search between 1993 and 1998. This collection imported all three, and inherited with them the phenomenon they answer — which is that randomising a search's choices is what makes the tail.

The interval is wider than the number

The field's most-quoted statistic — how far ahead of its evidence a popular date runs — is the mean of eight positive gaps, and it is quoted as three hundred and fifty-seven years. Resampling the fifteen entries puts ninety per cent of its weight between a hundred and fifty and five hundred and ninety-one. The interval is wider than the number, the middle gap's interval is a fifth as wide, and the difference is the same two documents the leave-one-out found.

The oldest book cuts the paper

The Hiden Senbazuru Orikata of 1797 is the earliest surviving book of recreational paper folding, and its famous connected cranes are made by slitting one sheet into a grid. The founding rule of the modern subject is younger than the tradition it claims to describe.

Two kinds of claim

This site has published a median overrun of two centuries and a mean of twenty-two years in the opposite direction, and both are right. Split the record by what each claim is about and the reason appears: every claim about a practice is dated earlier than its evidence, most claims about a result are dated later, and the two scatter by 979 years and 131.

Two traditions and a merge

Ceremonial wrapping, recreational folding and the kindergarten syllabus are three separate lineages with three separate purposes, and they were independent until the late nineteenth century. Told as one continuous tradition, the oldest date in any of them becomes the age of all three.

When two of them are first attested together

Every single date in this field is argued about by centuries, and a pairwise one is not. The earliest year at which two claims are both attested is simply the later of their two surviving sources, so it inherits the better-attested half of each pair rather than the worse — and the year at which all five lineages of practice are jointly on the record is 1838, one year from where the same claims are popularly dated together.

All the figures · The who found it, and when field · The patterns a reader can fold