how important is the diagonal plane of SW?

Valerie Sutton sutton at SIGNWRITING.ORG
Thu Nov 4 15:15:30 UTC 2010

SignWriting List
November 4, 2010

Hello Gan!
Thank you for this message and it is great news that you are so close to a milestone in your dissertation, "Automatic Hand Gesture Recognition for SignWriting". I can understand your concern, since you are not providing a product for the world, but just demonstrating that such a product could be produced (a glove that moves and writes SignWriting on computer screens). I have already seen a demo and I think it is a remarkable accomplishment.

I agree with you. Be at peace....your work with the Floor Plane and Wall Plane arrows is plenty to demonstrate this amazing development - You do not have to include the Diagonal Plane in my opinion, just as long as you state that it exists and needs to be included for future developments. Be sure to state the rare frequency of the Diagonal Arrows.

Here is how you find the frequency of use for symbols...

Attached is a screen capture of the Symbol Frequency feature in SignPuddle, for two dictionaries...the unedited ASL SignPuddle dictionary, and the edited German Sign Language SignPuddle dictionary. I clicked on the Symbol Frequency button and it shows how many times the Diagonal Arrows were used in both dictionaries, in comparison with how many times the arrows on the Floor Plane and the Wall Plane were used...Have you tried the Symbol Frequency feature in SignPuddle to see such comparisons?

As you can see by the attached screen capture...the Diagonal Arrows are rare in comparison to the Floor and Wall Planes:

US ASL Dictionary in SignPuddle 
Frequency Small Arrow Wall: 810
Frequency Small Arrow Diagonal: 29
Frequency Small Arrow Floor: 1052

DE German Sign Language Dictionary in SignPuddle
Frequency Small Arrow Wall: 1732
Frequency Small Arrow Diagonal: 23
Frequency Small Arrow Floor: 2092

So you can see that the Diagonal Arrows, in comparison to the Floor and Wall Planes, are rarely used....but they are used occasionally for a real reason - there are a few signs that require it because of meaning - like an airplane taking off at a diagonal -

Ironically, before I developed the Diagonal Arrow symbols, we could still write the diagonal plane, by combining a Floor and Wall Plane arrow side by side, but people did not read that combination well, and so that is why I developed the unique symbols.

Having said that, I feel that for your research, which is not a product used by the general public, but a demonstration to other companies that such a product could be produced, that you could simply mention in your dissertation that the Diagonal Planes do exist, but stating the above frequency ratios between the three planes, your dissertation does not work with the Diagonal Planes because it is too rare, but that a real product used by signers would need to include the rare need for Diagonal Arrows.

Please see attached diagram -

Val ;-)

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On Nov 4, 2010, at 5:29 AM, Gan Lu wrote:

> Hi val;
>    I'm on the verge of my thesis writing up for my research, and the Direct SignWritng system development is forming its shape. Some systematic testing and evaluations are conducting tensely recently to summarise my work. 
>   While our developed system's reference planes are divided into two, the wall and floor plane, we are aware there is another reference plane which is the 'diagonal plane', although it is seldom to see such plane in the SW literature. Is that possible to know how import or how often this plane is used in SW? 
>   The reason I'm asking is that I'm personally reluctant to implement it in my system by now, for it requires huge amount of work to do and will put off my deadline greatly. My intention is to demonstrate these two developed reference planes only at this stage to show the capability of the system, for we are not a company to produce a product after all, which should cover all functions. 
>    I would like to hear other people's opinion in terms of how important the 'diagonal plane' for SW as well. 
> Thanks very much for you all
>    Gan
> University of Central Lancashire

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