Chatbots can have varying levels of complexity and can be stateless or stateful. A stateless chatbot approaches each conversation as if it was interacting with a new user. In contrast, a stateful chatbot is able to review past interactions and frame new responses in context. Adding a chatbot to a company's service or sales department requires low or no coding; today, a number of chatbot service providers that allow developers to build conversational user interfaces for third-party business applications.
A basic SMS service is available via GitHub to start building a bot which uses IBM’s BlueMix platform which hosts the Watson Conversation Services. A developer can import a workspace to setup a new service. This starts with a blank dashboard where a developer can import all the tools needed to run the conversation service. The services has a dialog flow – a series of options with yes/no answers that the service uses to work out what the user’s intent is, what entity it’s working on, how to respond and how to phrase the response in the best way for the user.
In 1950, Alan Turing's famous article "Computing Machinery and Intelligence" was published, which proposed what is now called the Turing test as a criterion of intelligence. This criterion depends on the ability of a computer program to impersonate a human in a real-time written conversation with a human judge, sufficiently well that the judge is unable to distinguish reliably—on the basis of the conversational content alone—between the program and a real human. The notoriety of Turing's proposed test stimulated great interest in Joseph Weizenbaum's program ELIZA, published in 1966, which seemed to be able to fool users into believing that they were conversing with a real human. However Weizenbaum himself did not claim that ELIZA was genuinely intelligent, and the introduction to his paper presented it more as a debunking exercise: