  The introduction of Artificial Intelligence (AI) generative language models
such as GPT (Generative Pre-trained Transformer) and tools such as ChatGPT has
triggered a revolution that can transform how text is generated. This has many
implications, for example, as AI-generated text becomes a significant fraction
of the text, would this have an effect on the language capabilities of readers
and also on the training of newer AI tools? Would it affect the evolution of
languages? Focusing on one specific aspect of the language: words; will the use
of tools such as ChatGPT increase or reduce the vocabulary used or the lexical
richness? This has implications for words, as those not included in
AI-generated content will tend to be less and less popular and may eventually
be lost. In this work, we perform an initial comparison of the vocabulary and
lexical richness of ChatGPT and humans when performing the same tasks. In more
detail, two datasets containing the answers to different types of questions
answered by ChatGPT and humans, and a third dataset in which ChatGPT
paraphrases sentences and questions are used. The analysis shows that ChatGPT
tends to use fewer distinct words and lower lexical richness than humans. These
results are very preliminary and additional datasets and ChatGPT configurations
have to be evaluated to extract more general conclusions. Therefore, further
research is needed to understand how the use of ChatGPT and more broadly
generative AI tools will affect the vocabulary and lexical richness in
different types of text and languages.

Computation and Language;Artificial Intelligence