Generative artificial intelligences like ChatGPT or Google Bard are reshaping how we write. But how can we tell if a passage comes from a human mind or an algorithm? A research team built a machineβlearning model that can differentiate studentβwritten texts from those produced by five different LLMs. The approach uses two steps: binary classification (human vs. AI) and multiclass classification (human vs. each of the five models). They tested traditional algorithms such as Random Forest and recurrent neural networks, achieving 98.5% accuracyβfar higher than the wellβknown GPTZero (78.3%).
To understand *why* the model works, the authors applied Explainable AI (XAI), which highlights the most decisive features for each decision. These include sentence length, lexical variety, and recurring syntactic patterns. Such βstylistic fingerprintsβ create a unique profile for every author, human or artificial, aiding plagiarism detection and ensuring content originality. In practice, the system not only says βitβs AIβ but also explains which traits led to that conclusion. This approach could become a key tool for schools, publishers, and online platforms, where transparency about text provenance is increasingly vital.
