In terms of visual center, I have been discovering this is coming up with an "intuitive" way to write signwriting, as opposed to printing signwriting. A handwritten form of the letter "A" for example starts with the bottom left foot of the "A" goes to the top of the letter, down the other side, and then crosses the "A" with the center bar.

The same leap is used in my methods for teaching how to write an "index finger" hand for the right hand and the left hand using the visual center for the starting point of the sign. 

If one starts with the top corner of the square for the right and left hands for the index finger one discovers and interesting drawing methodology.

For either hand for the back of the hand, one draws away from the visual center to complete the square to end with the index finger.  For either hand for the edge-on or facing the reader, one draws the square toward the visual center in order to end the square where the index finger begins. 

This is different than the placement of that shape into a box in whatever direction and assembling multiple handshapes into a sign, but treating each handshape independently and using the visual center of the final placement to determine where to start actually writing the handshape has created a systematic way to draw handshapes that differentiates between left and right hands in production so that one can easily see differences even in hands with no visual difference, such as right and left handed front and back of the square hand.  The right and left hand are visually the same in printed form, but in handwritten form, in my system, they start in different places so one can see the right hand and the left hand, even when crossed or in an unusual place.

Thank you for your discussion of the "visual center" of the sign.  I will try to write it up as I continue to work on my Ethiopian sign language textbook, as it is a hard concept to describe in words, but much easier to point out in sign.

Charles

I found out that given a cluster of symbols, I can always determine the correct visual center.  No matter what symbols the writer used.  No matter where the writer placed the symbols.  A simple algorithm could find the center.  Very important for sign text layout. 

This vision has shaped the existing SignPuddle data.

I hope some of you share the same vision.
-Steve