Word usage in interactive dialog with restricted and unrestricted vocabularies

Based on the conclusion from a problem-solving experiment that people can adapt to communicating with restricted vocabularies, this paper examines the numbers and kinds of words used by the subjects, and determines what happens to people´s communication when the allowable vocabulary is decreased. First, the words used do not have much in common with high frequency words in two well-known word lists. Second, a great amount of individual variability was found even among subjects who worked with the most restricted vocabularies. As a result, the core vocabulary common to all, or almost all, of the subjects was surprisingly small. Third, vocabulary restrictions reduced the number of less common words used without any appreciable effect on the usage of the more common words. Finally, the findings suggest that small vocabularies can be successfully used provided they are tailored to their specific applications.