More rigorously testing the hoax hypothesis

[MarcoP]

I just read the two Malta papers by Gaskell and Bowern: they are excellent, not only for the corpora of cipher systems and human-generated gibberish they discuss, but also for the extensive set of quantitative measures applied when comparing with Voynichese.

This is a passage from "Gibberish after all?" (emphasis mine)

A more significant limitation of this work is that, because of the short length of our text samples, we are unable to test whether gibberish can replicate the larger structural features (such as “topic words”) which have been observed in the VMS [5–7]. At present, these features pose a serious challenge to proponents of the hoax hypothesis. However, while it is premature to assume that gibberish can replicate these features, it is equally premature to assume that it cannot; in theory, the properties of a scribe’s gibberish might drift considerably over the course of the weeks or months required to generate a VMSlength manuscript, introducing significant large-scale nonrandomness. If the scribe took breaks between sections, or only kept out material from the current section to reference when copying vocabulary, further spatial patterns might arise. 3 Insofar as possible, our results appear consistent with this hypothesis.

In my opinion, the way the vocabulary changes is at least as much of a problem for the idea of a meaningful text. As I already said in this thread, the degree of variation in lexicon is not compatible with the simple shift in topics. If one assumes that there is a one-to-one correspondence between Voynichese and plain-text (something like a nomenclator or Rene's thought experiment discussed above), the most frequent words should not change much with different topics. If there is no such correspondence, direct word-basis topic analysis does not make sense.

Also, I don't think I spotted anything in the other paper (Enciphered after all?) that could suggest that this drift is the effect of a cipher mechanism: I guess that one could resort to nulls or some ambiguous system where the scribes could make arbitrary choices according to preferences that varied during the production of the text.

Sadly, my first impression is that these papers shift the balance in favour of meaninglessness. Here is another passage from the paper:

Compared to meaningful texts, gibberish has lower mean information content (compression); lower mean conditional character entropy (entropy); higher mean occurrences of repeated characters and words (repeated_chars, repeated_words); higher mean bias in where characters appear in a line (charbias_mean) and where words appear in a 200-word section (wordbias_mean); higher mean autocorrelation of word lengths (wordlen_autocorr; see below)

The overlap of the features of gibberish with Voynichese is rather striking: low conditional character entropy, repeated words, bias for where characters appear in a line (line effects).