Turing test

The Turing test is a test proposed in 1950 by the mathematician Alan Turing to tackle the question of whether a machine can "think". In its classic form, a person holds a written conversation with two hidden participants — one human, one machine — and has to guess which is which; if they cannot reliably tell them apart, the machine is said to pass. The key idea is that it judges observable behaviour, not what happens inside: it measures whether the machine seems intelligent, not whether it truly understands. For that reason it has drawn famous criticism, such as John Searle’s "Chinese room" thought experiment. With the arrival of modern chatbots ✕ A chatbot is a program you converse with by text or voice. Modern ones use AI to understand and respond in natural language. More in the glossary → built on large language models ✕ An LLM is an AI model trained on huge amounts of text to understand and generate language. It is the engine behind assistants like ChatGPT. More in the glossary → , which are often indistinguishable from a person in a short chat, the test has returned to the centre of debate, and many experts now consider it insufficient as a real measure of intelligence.