I have finally found the time to read Jonas' paper.
The described approach is indeed very similar to the one discussed by Donald Fisk (see above). If I understand correctly, the main difference is that Donald treats space as a character while Jonas doesn't: personally, in the context of a glyph/sound correspondence, I favour Jonas approach, since space does not represent a sound. Of course, if glyphs do not represent sounds, considering the relationship with space could make more sense, but both Donald and Jonas appear to be exploring the "phonetic" line, discussing glyphs in terms of vowels and consonants. Though this assumption may be wrong, it still is the idea I favour the most: I am happy to see it explored under different approaches!
Both authors apparently only consider transitions from one character to the following one. The alternative would be to also consider transitions from each character to the one being examined, so that for an alphabet with C glyphs you get C*2 dimensions for each glyph X (aX Xa bX Xb cX Xc etc). I think that also considering the transition from the preceding character could result in more robust results: for instance, in English 'c' is often followed by the consonant 'k', by also considering the preceding character, words like 'black' or 'quick' will help correctly classifying 'c' as a consonant.
Since there is so much uncertainty about the VMS, it is always informative to see what happens with different set-ups. Once you have a computational tool in place, it is relatively easy to feed it multiple data-sets. E.g.:
I attach Fig.7 from Jonas' paper (you can ignore the boxed characters and focus on the non-boxed labels).
Coming back to comparing Donald's and Jonas' work, their results are similar in the fact that the "circle" EVA:o,a,y are somehow separated from the other glyphs: this is something on which most analyses tend to agree (e.g. You are not allowed to view links. Register or Login to view. Sukhotin experiments; it is also what Emma and I found in You are not allowed to view links. Register or Login to view., fig.4.1, based on very different data).
An important exception is You are not allowed to view links. Register or Login to view., that points out that 'y' does not seem to belong to the same class as 'o' 'a'.
Jonas' results about the "gallows" largely differ from other similar work: typically, the four gallows EVA:k,t,p,f are reported as behaving similarly, and the four benched gallows EVA:ckh,cth,cph,cfh are also reported as being close to each other. Here 'p' 'f' are opposite to 'k' 't' both along PC1 and PC2.
Jonas conclusion is that this method does not allow a clear separation into Vowels and Consonants. This is also what Rene found with HMM. Of course, these results suggest that the phonetic idea I favour is wrong.
The described approach is indeed very similar to the one discussed by Donald Fisk (see above). If I understand correctly, the main difference is that Donald treats space as a character while Jonas doesn't: personally, in the context of a glyph/sound correspondence, I favour Jonas approach, since space does not represent a sound. Of course, if glyphs do not represent sounds, considering the relationship with space could make more sense, but both Donald and Jonas appear to be exploring the "phonetic" line, discussing glyphs in terms of vowels and consonants. Though this assumption may be wrong, it still is the idea I favour the most: I am happy to see it explored under different approaches!
Both authors apparently only consider transitions from one character to the following one. The alternative would be to also consider transitions from each character to the one being examined, so that for an alphabet with C glyphs you get C*2 dimensions for each glyph X (aX Xa bX Xb cX Xc etc). I think that also considering the transition from the preceding character could result in more robust results: for instance, in English 'c' is often followed by the consonant 'k', by also considering the preceding character, words like 'black' or 'quick' will help correctly classifying 'c' as a consonant.
Since there is so much uncertainty about the VMS, it is always informative to see what happens with different set-ups. Once you have a computational tool in place, it is relatively easy to feed it multiple data-sets. E.g.:
- different transliteration systems (EVA, CUVA, 101, etc)
- different subsections of the VMS (Currier A/B, image-defined sections)
- different systems for computing glyph vectors (with/without spaces, only following glyphs, only preceding glyphs, both following and preceding glyphs)
I attach Fig.7 from Jonas' paper (you can ignore the boxed characters and focus on the non-boxed labels).
Coming back to comparing Donald's and Jonas' work, their results are similar in the fact that the "circle" EVA:o,a,y are somehow separated from the other glyphs: this is something on which most analyses tend to agree (e.g. You are not allowed to view links. Register or Login to view. Sukhotin experiments; it is also what Emma and I found in You are not allowed to view links. Register or Login to view., fig.4.1, based on very different data).
An important exception is You are not allowed to view links. Register or Login to view., that points out that 'y' does not seem to belong to the same class as 'o' 'a'.
Jonas' results about the "gallows" largely differ from other similar work: typically, the four gallows EVA:k,t,p,f are reported as behaving similarly, and the four benched gallows EVA:ckh,cth,cph,cfh are also reported as being close to each other. Here 'p' 'f' are opposite to 'k' 't' both along PC1 and PC2.
Jonas conclusion is that this method does not allow a clear separation into Vowels and Consonants. This is also what Rene found with HMM. Of course, these results suggest that the phonetic idea I favour is wrong.