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.

翻译：以GPT（生成式预训练Transformer）为代表的生成式人工智能语言模型及ChatGPT等工具的出现，已引发一场可能彻底改变文本生成方式的革命。这带来诸多潜在影响，例如：当AI生成文本在文本总量中占据显著比例时，是否会影响读者的语言能力以及新一代AI工具的训练？是否会改变语言的演化轨迹？聚焦于语言的一个特定维度——词汇层面：ChatGPT等工具的使用究竟会扩大还是缩减所用词汇量及词汇丰富度？这将对词汇产生深远影响，因为未包含在AI生成内容中的词汇将逐渐丧失使用频率，最终可能面临消亡。本研究对ChatGPT与人类在执行相同任务时的词汇量及词汇丰富度进行了初步比较。具体而言，我们采用两个数据集（分别包含ChatGPT与人类对各类问题的回答）以及第三个数据集（ChatGPT对句子和问题进行复述的内容）。分析表明，相较于人类，ChatGPT倾向于使用更少的独特词汇且词汇丰富度更低。这些结论尚属初步阶段，需通过更多数据集和ChatGPT配置的评估以得出更具普适性的结论。因此，有必要开展进一步研究，以深入理解ChatGPT及更广泛的生成式AI工具将如何影响不同类型文本及语言中的词汇量与词汇丰富度。