For every question or instruction input to the conversational bot, there must exist a specific pattern in the database to provide a suitable response. Where there are several combinations of patterns available, and a hierarchical pattern is created. In these cases, algorithms are used to reduce the classifiers and generate a structure that is more manageable. This is the “reductionist” approach—or, in other words, to have a simplified solution, it reduces the problem.
At this year’s I/O, Google announced its own Facebook Messenger competitor called Allo. Apart from some neat features around privacy and self-expression, the really interesting part of Allo is @google, the app’s AI digital assistant. Google’s assistant is interesting because the company has about a decades-long head start in machine learning applied to search, so its likely that Allo’s chatbot will be very useful. In fact, you could see Allo becoming the primary interface for interacting with Google search over time. This interaction model would more closely resemble Larry Page’s long-term vision for search, which goes far beyond the clumsy search query + results page model of today:
Chatbots – also known as “conversational agents” – are software applications that mimic written or spoken human speech for the purposes of simulating a conversation or interaction with a real person. There are two primary ways chatbots are offered to visitors: via web-based applications or standalone apps. Today, chatbots are used most commonly in the customer service space, assuming roles traditionally performed by living, breathing human beings such as Tier-1 support operatives and customer satisfaction reps.
3. Now, since ours is a conversational AI bot, we need to keep track of the conversations happened thus far, to predict an appropriate response. For this purpose, we need a dictionary object that can be persisted with information about the current intent, current entities, persisted information that user would have provided to bot’s previous questions, bot’s previous action, results of the API call (if any). This information will constitute our input X, the feature vector. The target y, that the dialogue model is going to be trained upon will be ‘next_action’ (The next_action can simply be a one-hot encoded vector corresponding to each actions that we define in our training data).
Eventually, a single chatbot could become your own personal assistant to take care of everything, whether it's calling you an Uber or setting up a meeting. Or, Facebook Messenger or another platform might let a bunch of individual chatbots to talk to you about whatever is relevant — a chatbot from Southwest Airlines could tell you your flight's delayed, another chatbot from FedEx could tell you your package is on the way, and so on.

One of the first stepping stones to this future are AI-powered messaging solutions, or conversational bots. A conversational bot is a computer program that works automatically and is skilled in communicating through various digital media—including intelligent virtual agents, organizations' apps, organizations' websites, social platforms and messenger platforms. Users can interact with such bots, using voice or text, to access information, complete tasks or execute transactions. 
2a : a computer program that performs automatic repetitive tasks : agent sense 5 Several shopping "bots" will track down prices for on-line merchandise from a variety of vendors.— Sam Vincent Meddis especially : one designed to perform a malicious action These bot programs churn away all day and night, prodding at millions of random IP addresses looking for holes to crawl through. — Jennifer Tanaka
Chatting with a bot should be like talking to a human that knows everything. If you're using a bot to change an airline reservation, the bot should know if you have an unused credit on your account and whether you typically pick the aisle or window seat. Artificial intelligence will continue to radically shape this front, but a bot should connect with your current systems so a shared contact record can drive personalization.

ELIZA's key method of operation (copied by chatbot designers ever since) involves the recognition of clue words or phrases in the input, and the output of corresponding pre-prepared or pre-programmed responses that can move the conversation forward in an apparently meaningful way (e.g. by responding to any input that contains the word 'MOTHER' with 'TELL ME MORE ABOUT YOUR FAMILY').[9] Thus an illusion of understanding is generated, even though the processing involved has been merely superficial. ELIZA showed that such an illusion is surprisingly easy to generate, because human judges are so ready to give the benefit of the doubt when conversational responses are capable of being interpreted as "intelligent".