The involvement of technological giants such as Microsoft and Google in the development of large language models (LLMs) for general public makes this technology likely to be soon omnipresent, since any activity on a computer highly depends on their products.
Despite the current global craze, LLMs are not a new technology. Its concepts were developed more than half a century ago. LLMs are, as described by ChatGPT itself, when prompted to provide a definition, “a type of artificial intelligence that have been designed to process and generate human-like text. These models are trained on vast amounts of data, such as books, articles, and websites, and use this information to learn about language and how it is used. As a result, large language models are able to generate coherent text that is difficult to distinguish from text written by a human”.
ChatGPT is based on an LLM called GPT-3.5 (GPT – Generative Pre-training Transformer), a neural network machine-learning model that uses the same pre-training datasets as its precursor GPT-3, which was released in 2020, with additional fine-tuning. This fine-tuning stage includes the incorporation of a concept called “reinforcement learning with human feedback“ (RLHF). ChatGPT is based on GPT-3.5, but works within even stricter guardrails on ethical standards, by introducing human values via strict ethical policies and rules to the model. It is assumed the list of these rules and policies was probably similar to the one published by DeepMind’s Sparrow, which was designed by DeepMind researchers, California Institute of Technology, University of Toronto, and University College Dublin (1, 2). Finally, ChatGPT was GPT optimized for dialogue (3).
GPT-4 is a large multimodal model, which accepts not only text, but also image inputs and delivers text outputs. It is more capable than its predecessor GPR-3.5 in terms of reliability, creativity and handling specific instructions. However, the limitations reported by OpenAI, seem to be similar to those of GPT-3.5, therefore, human review is still needed. (4)
In the previous blog post of this series, we have reported already on the first experiences with ChatGPT for medical writing tasks. In this blog post we focus on the significant limitations and pitfalls that need to be taken into account when using LLMs.