A chat bot is a computer program that is designed to engage in conversation with a human partner. This type of software is intended to convince its interlocutors that it is an active participant in the conversation and that real meaning is being exchanged. Some types of chat bot are even designed to make users believe that they are engaged in a conversation with a living human being. This type of program, although often employed purely for novelty value, is useful in psychological research, the development of artificial intelligence, and in handling some types of business interaction with customers.
The first program to function as a chat bot was ELIZA, a research tool developed in the 1960s. ELIZA was designed to simply parse comments from a human user and then respond with questions based on some of the words in the user input. Users found this fascinating and engaged in surprisingly protracted conversations with ELIZA, which they often interpreted as having been meaningful, thanks to the human predilection to find meaning in conversation.
A modern chat bot has access to many times more computing power than such early programs. Consequently, modern chat bots can often fool users for some period of time and many have good results in passing the Turing test. This test features a conversation between a human and a computer program. A program whose output cannot be distinguished from human conversation can be considered to have passed the test.
Many chat bots are designed for frivolous or nefarious purposes. Some users simply create bots and place them in chat or messaging sites on a lark. Others use these bots to distribute unwanted advertising or to harass users, although such advertising bots are relatively easy to screen out, as their constant dissemination of advertising information breaks their cover.
In 2011, recent years have seen this type of program come to serve more practical purposes, however. When contacting many large corporate or government entities, a human is now often greeted by an automated chat bot. These bots are now capable of performing many tasks once handled by human operators and are routinely used to collect user information, to direct calls to the appropriate department, or to handle simple tasks without any human intervention.
Chat bots are also used in the development of artificial intelligence. Any successful AI must be able to parse natural language and formulate appropriate responses. These are tasks for which a chat bot is already designed.