One pertinent field of AI research is natural language processing. Usually, weak AI fields employ specialized software or programming languages created specifically for the narrow function required. For example, A.L.I.C.E. uses a markup language called AIML, which is specific to its function as a conversational agent, and has since been adopted by various other developers of, so called, Alicebots. Nevertheless, A.L.I.C.E. is still purely based on pattern matching techniques without any reasoning capabilities, the same technique ELIZA was using back in 1966. This is not strong AI, which would require sapience and logical reasoning abilities.
In the early 90’s, the Turing test, which allows determining the possibility of thinking by computers, was developed. It consists in the following. A person talks to both the person and the computer. The goal is to find out who his interlocutor is — a person or a machine. This test is carried out in our days and many conversational programs have coped with it successfully.
Facebook Messenger chat bots are a way to communicate with the companies and services that you use directly through Messenger. The goal of chat bots is to minimize the time you would spend waiting on hold or sifting through automated phone menus. By using keywords and short phrases, you can get information and perform tasks all through the Messenger app. For example, you could use bots to purchase clothing, or check the weather by asking the bot questions. Bot selection is limited, but more are being added all the time. You can also interact with bots using the Facebook website.
Of course, each messaging app has its own fine print for bots. For example, on Messenger a brand can send a message only if the user prompted the conversation, and if the user doesn't find value and opt to receive future notifications within those first 24 hours, there's no future communication. But to be honest, that's not enough to eradicate the threat of bad bots.