SignTutor: An Interactive System for Sign Language Tutoring
From: IEEE Computer Society Computing Now - 05/20/2009

Sign language recognition (SLR) is a multidisciplinary research area
involving pattern recognition, computer vision, natural language processing,
and linguistics. The concept presents a multifaceted problem not only because
of the complexity of the visual analysis of hand gestures, but also due to
the highly multimodal nature of sign languages. Although sign languages are
well-structured languages with a phonology, morphology, syntax, and grammar,
they are different from spoken languages. 

From:
http://www2.computer.org/portal/web/computingnow/0509/whatsnew/multimedia

Read the entire article at:
http://www2.computer.org/cms/Computer.org/ComputingNow/homepage/2009/0509/rW_MM_SignTutor.pdf