> This approach, which we call DetectGPT, does not require training a separate classifier, collecting a dataset of real or generated passages, or explicitly watermarking generated text. It uses only log probabilities computed by the model of interest and random perturbations of the passage from another generic pre-trained language model (e.g, T5).

Very interesting, though the passage above makes me wonder how robust it is to different models or even finetuned variations on models, as even GPT-3(.5) has evolved quite a bit over recent releases since its initial introduction, and there is likely to only be a greater and greater proliferation of models over time.