ChatGPT

ChatGPT, which stands for Chat Generative Pre-trained Transformer, is a large language model-based chatbot developed by OpenAI and launched on November 30, 2022, that enables users to refine and steer a conversation towards a desired length, format, style, level of detail, and language. Successive prompts and replies, known as prompt engineering. OpenAI now operates the service on a freemium model. It allows users on its free tier to access the GPT-3.5-based version. In contrast, the more advanced GPT-4-based version and priority access to newer features are provided to paid subscribers under the commercial name “ChatGPT Plus”. By January 2023, it had become what was then the fastest-growing consumer software application in history, gaining over 100 million users. Microsoft launched its Bing Chat based on OpenAI’s GPT-4. It raised concern among some observers over the potential of ChatGPT and similar programs to displace or atrophy human intelligence, enable plagiarism, or fuel misinformation.

Features and limitations

Features: Although a chatbot’s core function is to mimic a human conversationalist, ChatGPT is versatile. Among countless examples, it can write and debug computer programs; compose music, teleplays, fairy tales, and student essays; answer test questions (sometimes, depending on the test, at a level above the average human test-taker); generate business ideas; write poetry and song lyrics; translate and summarize text; emulate a Linux system; simulate entire chat rooms; play games like tic-tac-toe; or simulate an ATM.

Unlike most chatbots, ChatGPT remembers a limited number of previous prompts in the same conversation. Journalists have speculated that this will allow ChatGPT to be used as a personalized therapist. To prevent offensive outputs from being presented to and produced by ChatGPT, queries are filtered through the OpenAI “Moderation endpoint” API (a separate GPT-based AI), and dismiss any potentially racist or sexist prompts.

In March 2023, OpenAI added support for plugins for ChatGPT. This includes both plugins made by OpenAI, such as web browsing and code interpretation, and external plugins from developers such as Expedia, OpenTable, Zapier, Shopify, Slack, and Wolfram.

Limitations: OpenAI acknowledges that ChatGPT “sometimes writes plausible-sounding but incorrect or nonsensical answers”. This behavior is common for large language models, and is called “hallucination”. The reward model of ChatGPT, designed around human oversight, can be over-optimized and thus hinder performance, in an example of an optimization pathology known as Goodhart’s law.

ChatGPT has limited knowledge of events that occurred after September 2021.

In training ChatGPT, human reviewers preferred longer answers, regardless of actual comprehension or factual content. Training data also suffers from algorithmic bias, which may be revealed when ChatGPT responds to prompts including descriptors of people. In one instance, ChatGPT generated a rap in which women and scientists of color were asserted to be inferior to white male scientists.

GPT-4

OpenAI’s GPT-4 model was released on March 14, 2023. Observers saw it as an impressive improvement on the existing GPT-3.5 model for ChatGPT, with the caveat that GPT-4 retained many of the same problems. Some of GPT-4’s improvements were predicted by OpenAI before training it, while others remained hard to predict due to breaks in downstream scaling laws. OpenAI demonstrated video and image inputs for GPT-4, although such features remain inaccessible to the general public. OpenAI has declined to reveal technical information such as the size of the GPT-4 model.

The ChatGPT Plus subscription service offers access to a GPT-4-powered version of ChatGPT. Microsoft acknowledged that Bing Chat was using GPT-4 before GPT-4’s official release.