The race to teach sign language to computers
Why paying attention to what deaf users actually want is vital. "As with spoken languages, sign languages — of which the world has several hundred — possess their own grammars, idioms and dialects. Again like spoken languages, the hard-and-fast rules of grammar books do not really capture the subtleties of everyday usage. Single signs can be shorthand for complex ideas. Like speakers, signers often take shortcuts, such as representing two-handed signs with a single hand. They set up reference points within their signing space which can be vital for meaning. Correctly interpreting all this is much harder than recognising spoken syllables or written letters."
From The Economist