The Ethnologue is an encyclopedic reference work cataloging all of the world’s 7,111 known living languages.
Ethnologue uses the EDGIDS Scale
The EGIDS consists of 13 levels with each higher number on the scale representing a greater level of disruption to the intergenerational transmission of the language. Table 1 provides summary definitions of the 13 levels of the EGIDS.
All Sign Languages exist within the middle range of educational to dormant, with 98/ 143 in the developing category.
Despite having sign language in the constitution, one of Finland's two official sign languages is considered severely Endangered.
Austria and New Zealand also have recognized their sign languages in their constitutions and yet they are considered vulnerable.
Levels of endangerment
1 = Critically
2 = Severely endangered
3 = Definitely endangered
4 = Vulnerable
Deaf students at all levels seem to be better off academically and socially if they are bilingual rather than monolingual. There are well-documented benefits to learning a signed language and no evidence of negative consequences. As researchers and educators, we believe that add-ing a natural sign language to the environment will have a positive impact on most deaf children’s cognitive, language, social, and educational development regardless of their hearing levels.
Marschark and Hauser (2012)