Reading #29: Scratch Input Creating Large, Inexpensive, Unpowered and Mobile Finger Input Surfaces (Harrison)

Summary

In this paper a new form of inputting sketch is assessed which is through the sound of fingernails upon a textured surface such as wood. They employ a stethoscope for this purpose which can be attached to walls and tables.
They evaluated their system on a hand designed set of gestures which consisted of six gestures. The accuracy over that set was about 90%

Discussion

I am really not optimistic about the prospect of this type of work, while the electronic input devices prices are dropping, why reverting back to this unreliable method. I think more compelling reasons are necessary