Most of our understanding of the history and diversity of human language and language change comes from research on spoken languages. The literature on historical linguistics suggests that language change should occur in particular specifiable directions. At the SLRL, we are working to determine whether these universals of language evolution apply to sign languages as well.
Cross-linguistic and cross-dialect comparative research can also shed light on universal patterns of language evolution in signed languages. Despite our growing understanding of sign languages, particularly ASL, there is still a dramatic and profound limitation on the availability of literary, linguistic, historical and other reference materials related to sign languages. In large part, this is because there is no commonly used writing system for signed languages. The existing literature is therefore transmitted 'orally' and not represented in print. Such materials are critical for scholars interested in historical, linguistic, cognitive or literary studies.
In the early part of this century, the National Association of the Deaf (NAD) created a set of films of the most fluent 'sign masters' of the time. Their goal was to preserve and demonstrate the sign language of the epoch. Twenty-two films were made between 1910 and 1920, fourteen of which have survived. They featured speeches, poetry and stories performed by twelve master signers. The master signers were of different ages, providing a sample of three generations of ASL users at the time. The original copies of the NAD films are stored in the archives of Gallaudet University and the Library of Congress. In 1997, Sign Media, Inc. produced a videotape copy of the NAD films. These films have turned out to be a rich source of material for analyses of historical change in ASL.
Our ultimate goal is to build a comprehensive platform to store and access not only the NAD films and early dictionaries, but to link these with data from other languages both historical and modern to expand the ability of researchers to do effective comparative analyses. To date, the SLRL has developed different types of database work using the NAD films and historical sign language dictionaries produced around the same time. Additional information not in the databases about the films and dictionaries can be found under Films & Dictionaries Toolkit.