  Aim: To compare students' essay writing performance with or without employing
ChatGPT-3 as a writing assistant tool. Materials and methods: Eighteen students
participated in the study (nine in control and nine in the experimental group
that used ChatGPT-3). We scored essay elements with grades (A-D) and
corresponding numerical values (4-1). We compared essay scores to students'
GPTs, writing time, authenticity, and content similarity. Results: Average
grade was C for both groups; for control (2.39, SD=0.71) and for experimental
(2.00, SD=0.73). None of the predictors affected essay scores: group (P=0.184),
writing duration (P=0.669), module (P=0.388), and GPA (P=0.532). The text
unauthenticity was slightly higher in the experimental group (11.87%, SD=13.45
to 9.96%, SD=9.81%), but the similarity among essays was generally low in the
overall sample (the Jaccard similarity index ranging from 0 to 0.054). In the
experimental group, AI classifier recognized more potential AI-generated texts.
Conclusions: This study found no evidence that using GPT as a writing tool
improves essay quality since the control group outperformed the experimental
group in most parameters.
