Nintendo data

The original sign language data was captured using a single Nintendo Powerglove, connected through a Powerglove Serial interface to a Silicon Graphics 4D/35G. A subset of Auslan consisting of 95 signs was selected to cover all the typical handshapes and movements. In some cases, signs that were difficult to distinguish were deliberately chosen. A complete list of the signs chosen can be found in Appendix B of [Kad95]. For convenience, a table from [Kad95] is shown Table 6.11, giving an overview of the sign selection process.

Table 6.11: Some statistics on the signs used.

Item	Number
	of signs
Total number of signs	95
Hand usage
- One-handed	59
- Double-handed	27
- Two-handed	9
Reasons for selection
- Common sign	66
- Similarity to other signs	11
- Uncommon Handshape	9
- Sign Complexity	5
- Other	4

The Powerglove proved itself to be a less than stellar performer. The x, y and z position are encoded as 8-bit values. Because it used ultrasound to compute position, it was quite susceptible to bogus echoes. Finger bend was only available for the first four fingers, and then, only two bits. Even more disastrously, the fingers were subject to hysteresis and unpredictability. No orientation information was available other than roll, which could take one of 12 values (i.e. measurements were +/- 30 degrees). Hence, in total, there were eight channels (x, y, z, roll, thumb, fore, middle, ring).

Further, the refresh rate was very low; approximately 23 to 25 frames per second. Finally, the glove only captured one hand, as there are no left-handed Powergloves.

Data was collected from several individuals. However for these experiments we used one individual. A total of 20 samples were collected from the signer for a total of 1900 signs.