It seems the authors implicitly chose the Flan-T5-XL model based on a previous paper they refer where it outperformed prompted engineered ChatGPT 3.5 and 4 on a

It seems the authors implicitly chose the Flan-T5-XL model based on a previous paper they refer where it outperformed prompted engineered ChatGPT 3.5 and 4 on a slightly different but similar task. This should definitely need to be further explained and possibly confirmed on their tasks. "Our best-performing fine-tuned models outperformed zero- and few-shot performance of ChatGPT-family models [...]" from Large language models to identify social determinants of health in electronic health records (https://arxiv.org/abs/2308.06354 https://arxiv.org/abs/2308.06354)