Simple NLP Techniques for Expanding Telegraphic Sentences

Some people have disabilities which make it difficult for them to speak in an understandable fashion. The field of Augmentative and Alternative Communication (AAC) is concerned with developing methods to augment the communicative ability of such people. Over the past 9 years, the Applied Science and Engineering Laboratories (ASEL) at the University of Delaware and the duPont Hospital for Children, has been involved with applying natural language processing (NLP) technologies to the field of AAC. One of the major projects at ASEL (The COMPANSION project) has been concerned with the application of primarily lexical semantics and sentence generation technology to expand telegraphic input into full sentences. While this project has shown some very promising results, its direct application to a communication device is somewhat questionable (primarily because of the computational power necessary to make the technique fast). This paper describes some of the problems with bringing Compansion to a standard communication device and introduces some work being done in conjunction with the Prentke Romich Company (PRC) (a well known communication device manufacturer) on developing a pareddown version of Compansion for people with cognitive impairments. 1 I n t r o d u c t i o n Some people have disabilities which make it difficult for them to speak in an understandable fashion. The field of Augmentative and Alternative Communication (AAC) is concerned with developing methods to augment the communicative ability of such people. In addition to problems that make "speaking" difficult, AAC users often have difficulties in coordinating extremities (so typing on a standard keyboard may be impossible and access to large keys is often very slow). Cognitive difficulties may also be present. The field of AAC is concerned with developing methods that provide access to communicative material under reasonable time and cognitive constraints. Over the past 9 years, the Applied Science and Engineering Laboratories (ASEL) at the University of Delaware and the duPont Hospital for Children, has been involved with applying natural language processing (NLP) technologies to the field of AAC. One of the major projects at ASEL (The COMPANSION project) has been concerned with the application of primarily lexical semantics and sentence generation technology to expand telegraphic input into full sentences (McCoy et al., 1989), (Demasco and McCoy, 1992), (McCoy et al., 1994). The project can best be thought of as a rate enhancement technique used in the context of a writing tool. Assuming the user is selecting full words at a time (so time of word selection is basically constant and is independent of the number of letters iri the word), the technique shows the most gain when used by a linguistically sophisticated user who desires well-formed English constructions. The system speeds rate by allowing the user to select basic content and having the system provide expansions into well-formed sentences. The user may then select among the generated expansions with 1 additional keystroke (for example). Consider the following input: Mary think 3 watch give John Andrew.