Chronological Path Stability/Uncertainty Analysis
#1
This is a follow-up analysis to my You are not allowed to view links. Register or Login to view. All of the code for this work can be found in the You are not allowed to view links. Register or Login to view..



Problem / Goal



The goal of this analysis was to answer "how uncertain / unstable are points on the proposed chronology". In particular, some follow-up analysis I have been conducting shows high sensitivity around the inclusion of f58, suggesting the placement of the missing H quire could change the ordering.

The core problem is, when tracing a path, the ends of the path have the least certainty. This is because points in the middle of the path have preceding and following points, which also have preceding / following points. These multiple overlapping observations provide much more certainty about the ordering. 

However, points on the end do not have this. By definition, the first and final points would only have either a preceding or following connection. Depending on the direction and amount of movement, this can create uncertainty around which group is the first or last.

f58 and the missing H bifolio add this same uncertainty in the middle of the manuscript. We are missing part of the path, which creates additional uncertainty, specifically in the Herbal B ordering.



Method



I tested the ordering stability using both 207 individual pages and 50 pooled bifolia, holding the transition-distance/MDS representation fixed. 

I utilized the ensemble procedure described in You are not allowed to view links. Register or Login to view.  which involves fitting curves to 100 random approximately 90% subsets, using eight starting routes and two regularization settings. A whole-bifolium sampling control brought the total to 4,800 fits.I then compared recurring positions, order reversals and competing routes’ scores within each sample. 

I ran You are not allowed to view links. Register or Login to view. to attempt to identify any discontinuous regions along the gradient.

To establish toe potential impact of the missing pages, and the creation of the the H-position MDS charts below, I used the You are not allowed to view links. Register or Login to view., applied derivative-based continuation at λ=.01, checking assignment changes and different movement paths.


A You are not allowed to view links. Register or Login to view. of exactly how each methodology was applied can be found on the voynich-clusters web page. All code is You are not allowed to view links. Register or Login to view.



Results



Instability Across the Gradient

The chart below shows the variance in the ordering of the individual pages based on different ensemble simulations described in ElPiGraph's paper. This shows where across the 4,800 different fit variants each page and bifolia fell. This allows us to determine how sensitive the positioning is to different starting conditions, assumptions, and modeling parameters. Darker regions indicate more variants placed the page in that area.

   

Observations from the chart:
  • the ordering with respect to 1a and 1b is ambiguous, however 1a pages generally exhibit a slight initial ordering preference over 1b
  • 1.5a and 2a's placements are generally stable. 
  • f58, astro and cosmo are generally stable as a group. The only exception is Rosettes, which is the single isolated band not with the others in 5a, on the page level chart. It clearly was not made at the same time as the other 5a group, probably instead being produced alongside the Herbal B sections, but possibly even being made as late as stars 3c.
  • Herbal 3a and 3b's ordering is not stable, and will be discussed below in the next section. 
  • At the bifolium level Stars 3c is generally stable, with f85r1 and r2 (the two unassigned bars ) also having the strongest preference for the same timing.
  • Bio / Stars 4c are more ambiguous, with fits generally preferring the ordering Stars 4c-> Bio



Checking for discontinuity 

scEGRET is a method described by Zheng et al that applies directly to our problem. It is a toolkit designed to follow paths and identify discontinuous regions, allowing us to more firmly establish if we are missing any sections of the overall curve. The code is freely available on the authors github.

The general idea is this, along a well sampled progression, successive groups should generally change gradually. An unusually large change indicates the trajectory crosses a gap, for example, because intermediate data is missing. 


scEGRET identifies no fully discontinuous regions across the gradient. Note, this does not mean certain areas along the curve are not missing pages. It simply means scEGRET was unable to detect one. 


F58 does show a modest local signal. The scEGRET scores measuring relative change jump from .184 to .271, around a 1.5x increase. Calibration places this within the 95% confidence region. Removing f58 along with adjacent astro material entirely does produce discontinuity flags, but it depends on certain model settings and is therefore not conclusive.

So there appears to be no obvious gaps in the gradient, f58's region appears suspicious but is not enough to claim the region is discontinuous. 



Impact of Missing Quire H on Herbal B

The chart below shows the impact the missing Quire H bifolia could have on the ordering of Herbal B's 3a/3b sections. 
  • This is using the same MDS dimensions as the plots in the previous chronology theory, 
  • The star shows the current placement of f58, the only remaining portion of quire H. 
  • The colors indicate which ordering of 3a and 3b is preferred, based on where the missing pages of quire H would shift the current Quire H centroid on the MDS dimensions
  • Red regions mean if the missing pages shift the centroid there, the preferred ordering is 3a->3b. If the missing bifolia instead shift the centroid into the blue regions, then the preferred ordering is 3b->3a. 
  • The black line divides the frontier between these regions


   

You can see the current f58 placement is almost directly on this red/blue frontier. This means without those missing pages, it is probably not possible to say for certain which Herbal B group comes first, because any slight changes from the current f58 point could alter the ordering.



Conclusion



The overall gradient is clear, but how confident we can be around the relative ordering of certain sections along that gradient varies. The  largest uncertainty is:
  • The ordering of Early Herbal A sections 1a and 1b, although 1a is generally preferred as the starting point
  • The ordering of 3a and 3b, basically indeterminant without the missing Quire H
  • The ordering of 4c and 4a / Stars-T and Bio is indeterminant, although bio is generally preferred as the endpoint.
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#2
How stable are the assignments and order when you use RF1b-er (basic_EVA) instead of the ZL transliteration?
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#3
(16-10-2026, 11:23 PM)nablator wrote: You are not allowed to view links. Register or Login to view.How stable are the assignments and order when you use RF1b-er (basic_EVA) instead of the ZL transliteration?

I reran the exact same process using EVA and RF1b/er, the results are almost the same. I generated the same chart as above, displaying the page and bifolio views from both together. They look almost identical, only some slight differences. 

   
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#4
(16-10-2026, 10:19 PM)npcompl33t wrote: You are not allowed to view links. Register or Login to view.This is a follow-up analysis to my You are not allowed to view links. Register or Login to view. All of the code for this work can be found in the You are not allowed to view links. Register or Login to view..

Thanks for posting these results!

I still disagree that the ordering of sections based on any textual statistics can be interpreted as chronological order.  But let's leave that discussion for other posts.  Here is what those plots tell me about the clustering of pages and bifolios, and your splitting of the usual sections (defined by image topic and A/B language) into sub-sections:
  1. I see no evidence in those plots that Herbal 1a and 1b should be separate sub-sections.   
  2. Ditto for Herbal 3a and 3b. 
  3. Ditto for Stars 5a and 6.
  4. Stars 3c and 4c look like they belong together too.
  5. There are some single pages that look like they don't belong to their assigned sub-sections: maybe two pages each in 1.5a and 2a, one in 3b, two in 5a.  
Stars S-3c and S-4c look very different in those plots. But here is what I think is probably happening (in a suitable projection of R^256 to R^2:
   
In this proposed interpretation, subsections S-3c and S-4c are just two parts of the same cluster that happens to be elongated in a direction perpendicular to the direction d that the curve fitting algorithm usually chooses as the independent variable t (the horizontal axis on those plots).  Presumably that is the direction of "maximum extent" of the whole dataset as given by PCA or some similar method.  

Because of that choice for d, the fitted curves, like C1 and C2, will generally follow similar paths.  Apparently they will go though or near 4c mostly at the same parameter value t0 = 0.85.  But the curves may happen to fall on two main classes that have different mean tangent directions at t0.  Then, depending of the curve's class, the 3c part of that cloud may project onto the curve either before or after t0 (green and red arrows).

The bimodal plot of B-4a may have a similar explanation.  That cloud presumably lies close to the t0 point too, but a bit further off the average curve.  Then, depending on the curve's class, it may project onto the curve either before or after t0.

The two classes of curves may be due to either the choice of d or the output of the curve fitting algorithm being a discontinuous function of whatever parameter is  varied to obtain different cures.  For example, imagine three equal clouds of data points at the corners of a pointy isosceles triangle.  Maybe the algorithm would have a tendency to pick a direction d along either of the two long sides, rather than along the longest median.

Sections 5a and 6 look almost identical on the second plot. The faint smudge to the right of 6 may be due to the same cause for 3c and 4c proposed above.  Namely 5a and 6 are just two parts of a singe cloud that is elongated in such a direction that for some curves the 6 part projects at t = 0.75, instead of t = 0.6; whereas 5a, being closer to the curve, always projects around t = 0.6.

As for item 5, the marked difference between those "oddball" pages and the rest of their assigned sub-sections may be an argument against your thesis.  Presumably they are pages with no images, or with "unclassified" images, that got placed in those sub-sections only because they were in the same bifolios as other classifiable pages -- is that correct?  If so, then either
<A> Those pages have different statistics because they were written long after the other pages on the same bifolios, or
<B> Those pages were written at the same time as the rest of their bifolios, but have different statistics because they are about different topics structure.
I don't see why <A> should be more likely than <B>.

All the best, --stolfi
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#5
(17-10-2026, 07:20 AM)Jorge_Stolfi wrote: You are not allowed to view links. Register or Login to view.
(16-10-2026, 10:19 PM)npcompl33t wrote: You are not allowed to view links. Register or Login to view.This is a follow-up analysis to my You are not allowed to view links. Register or Login to view. All of the code for this work can be found in the You are not allowed to view links. Register or Login to view..

Thanks for posting these results!

I still disagree that the ordering of sections based on any textual statistics can be interpreted as chronological order.  But let's leave that discussion for other posts.  Here is what those plots tell me about the clustering of pages and bifolios, and your splitting of the usual sections (defined by image topic and A/B language) into sub-sections:
  1. I see no evidence in those plots that Herbal 1a and 1b should be separate sub-sections.   
  2. Ditto for Herbal 3a and 3b. 
  3. Ditto for Stars 5a and 6.
  4. Stars 3c and 4c look like they belong together too.
  5. There are some single pages that look like they don't belong to their assigned sub-sections: maybe two pages each in 1.5a and 2a, one in 3b, two in 5a.  

I think you might be misunderstanding the plots. The plots are showing where certain sections may appear across many runs. They are not saying that these sections are shuffled in together in some runs. 

On the contrary, the sections are grouped together and the entire section shifts. In some cases, this effect is so strong that it completely denies content from another section from occupying certain regions, which is what you see with the purple stars section and the bio/yellow stars. Since the above plots combine the positions from all runs, entire sections moving vs individual pages moving look the same. It is not showing what your drawing indicates, and these plots are not even capable of making that distinction, because that was not the goal.

The goal of this post was not to establish these sections move together, I've already done that in the other threads, and i'm happy to continue the debate there. I'm still waiting to see your results running the test you specified with respect to your R^N bet! 

So 3a and 3b may have their orders reversed, but they do not have their pages shuffled together when that happens.  The plot is showing both situations together, which is why they appear overlapping, but it should not be used to estimate group cohesion, because it lacks the relevant information. Again, if you look at the plots in MDS space, it is clear they do form distinct groups.

I did explicitly run a technique designed to identify discontinuous segments of a path. If what you are saying is true, and the sections are not actually connected, or have discontinuous regions between them, then the scEGRET method i used would have detected that. Deleting f58 and some adjacent astro/cosmo pages does cause some of these indicators to activate, but only with certain hyperparameters, so even removing entire segments of the path is not enough to create discontinuous segments. 


Hope that makes sense!
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#6
(17-10-2026, 03:40 PM)npcompl33t wrote: You are not allowed to view links. Register or Login to view.
Deleting f58 and some adjacent astro/cosmo pages does cause some of these indicators to activate, but only with certain hyperparameters, so even removing entire segments of the path is not enough to create discontinuous segments. 

Quire 8 is just weird.  Half of it looks like typical plant pages and the other half is just strange unidentified stuff.
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#7
(17-10-2026, 04:01 PM)pjburkshire wrote: You are not allowed to view links. Register or Login to view.Quire 8 is just weird.  Half of it looks like typical plant pages and the other half is just strange unidentified stuff.

When Cary and I were looking at A vs B plants images, I realized just how much of a mess Q8 is. From my You are not allowed to view links. Register or Login to view. about it:

Quote:The situation in both bifolios of Quire 8 can be summarized as follows, with red indicating A and blue indicating B. The image types “starred text” and “diagram” are marked blue (B) since in the manuscript as a whole they are typically done by B-scribes.
[Image: image-19.png]
We see that almost every page of this quire has a mix of A and B indicators. Not a single row is completely red or blue.
  • f57r: B-scribe 5 writes two different types of B-language on the same page and the accompanying image is strongly A.
  • f57v: A-scribe 1 writes the text for a circular diagram. All other circular diagrams are done by B-scribes.
  • f58r and f58v: B-scribe 3 writes starred-text pages but the language is A!
  • f65r: the only plant page with hardly any text. B-scribe 3. Plant leans slightly A.
  • f65v: B-scribe 3, plant leans A.
  • f66r: a text-only page without stars is exceptional in the MS.
  • f66v: B-scribe 5 writes B-text, the plant is strongly A.

It is good to be aware of these things when looking at page order.

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#8
(17-10-2026, 04:15 PM)Koen G wrote: You are not allowed to view links. Register or Login to view.
When Cary and I were looking at A vs B plants images, I realized just how much of a mess Q8 is. 

That's true.  I forgot that You are not allowed to view links. Register or Login to view. is not a typical plant page since it has so little text.
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#9
(17-10-2026, 04:15 PM)Koen G wrote: You are not allowed to view links. Register or Login to view.When Cary and I were looking at A vs B plants images, I realized just how much of a mess Q8 is. From my You are not allowed to view links. Register or Login to view. about it:

Quote:The situation in both bifolios of Quire 8 can be summarized as follows, with red indicating A and blue indicating B. The image types “starred text” and “diagram” are marked blue (B) since in the manuscript as a whole they are typically done by B-scribes.
[Image: image-19.png]
We see that almost every page of this quire has a mix of A and B indicators. Not a single row is completely red or blue.
  • f57r: B-scribe 5 writes two different types of B-language on the same page and the accompanying image is strongly A.
  • f57v: A-scribe 1 writes the text for a circular diagram. All other circular diagrams are done by B-scribes.
  • f58r and f58v: B-scribe 3 writes starred-text pages but the language is A!
  • f65r: the only plant page with hardly any text. B-scribe 3. Plant leans slightly A.
  • f65v: B-scribe 3, plant leans A.
  • f66r: a text-only page without stars is exceptional in the MS.
  • f66v: B-scribe 5 writes B-text, the plant is strongly A.

It is good to be aware of these things when looking at page order.

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I think I may have seen a video of you going through these on your youtube channel, but didn't pick up the significance around these pages.

This in general i think does support the idea of this being a transitional section between A and B -- here we see the plants are still showing A markers while the language smoothly crosses the delineation between A and B.  Ive written about f58 before, while it is officially 'Currier A', that is a bit of a stretch, it is quite different from other A text.

In my chronological sequence, this would actually be the first section that scribes other than LFD hand 1 were working on the manuscript. 

As someone who has done far more extensive research into the herbal illustrations, how significant in your opinion is it that the flowers on 65v are not colored? The single 3 words there mean its text can't be reliably classified (though atypically they all end in m), but to me it looks like the page is unfinished.
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#10
The only color that is significant in the herbal section, in my opinion, is red. Red is freely available in Herbal A, but becomes very scarce in Herbal B. Q8 has no red.

Tracking the use of red will certainly be a piece of the puzzle for ordering the pages (in my opinion, the talk about much later painters, and thus irrelevant colors, is pure speculation).

That said, we also encountered some weird plant behavior in some of the 50's folios, which may also be transitional. For example, 55r has an attempt at red while it shouldn't, and 55v has the wrong shape for a B-folio.
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