At present, the study of syntax and semantics has yielded certain results in the field of computational linguistics, while pragmatics has not been paid as much attention. The lack of paralinguistic research, the research of body language, is obvious. Among numerous definitions of body language we will use two in this paper: firstly, gestures, postures and face expressions accompanying speech or occurring independently, and secondly, it is a language used by deaf and mute people, or sign language.
Body language, in its first meaning plays an auxiliary role in language understanding but is also of vital importance for disambiguation. Body language in its second meaning is the only communication tool for mute and deaf people. In order to help them to become full members of the society and to remove communication barriers, scholars should pay more attention to the research of sign language.
The first step of natural language processing is its formalization. Usually tagging or labeling is meant by formalization. It is not a challenge for text processing anymore, but for body language processing one should deal with video, that is why there has been little research conducted in the field of computational linguistics so far. To date, most of body language research is highly descriptive and lacks formality, thus cannot be used in computational linguistics.