This is a lot less complicated than it appears. Given a set of sentences, each belonging to a class, and a new input sentence, we can count the occurrence of each word in each class, account for its commonality and assign each class a score. Factoring for commonality is important: matching the word “it” is considerably less meaningful than a match for the word “cheese”. The class with the highest score is the one most likely to belong to the input sentence. This is a slight oversimplification as words need to be reduced to their stems, but you get the basic idea.

Niki is a personal assistant that has been developed in India to perform an impressively wide variety of tasks, including booking taxis, buses, hotels, movies and events, paying utilities and recharging your phone, and even organizing laundry pickup and delivery. The application has proven to be a huge success across India and won the Deep Tech prize at the 2017 AWS Mobility Awards.
It didn’t take long, however, for Turing’s headaches to begin. The BabyQ bot drew the ire of Chinese officials by speaking ill of the Communist Party. In the exchange seen in the screenshot above, one user commented, “Long Live the Communist Party!” In response, BabyQ asked the user, “Do you think that such a corrupt and incompetent political regime can live forever?”
Aside from being practical and time-convenient, chatbots guarantee a huge reduction in support costs. According to IBM, the influence of chatbots on CRM is staggering.  They provide a 99 percent improvement rate in response times, therefore, cutting resolution from 38 hours to five minutes. Also, they caused a massive drop in cost per query from $15-$200 (human agents) to $1 (virtual agents). Finally, virtual agents can take up an average of 30,000+ consumers per month.
For each kind of question, a unique pattern must be available in the database to provide a suitable response. With lots of combination on patterns, it creates a hierarchical structure. We use algorithms to reduce the classifiers and generate the more manageable structure. Computer scientists call it a “Reductionist” approach- in order to give a simplified solution, it reduces the problem.

Like apps and websites, bots have a UI, but it is made up of dialogs, rather than screens. Dialogs help preserve your place within a conversation, prompt users when needed, and execute input validation. They are useful for managing multi-turn conversations and simple "forms-based" collections of information to accomplish activities such as booking a flight.
Getting the remaining values (information that user would have provided to bot’s previous questions, bot’s previous action, results of the API call etc.,) is little bit tricky and here is where the dialogue manager component takes over. These feature values will need to be extracted from the training data that the user will define in the form of sample conversations between the user and the bot. These sample conversations should be prepared in such a fashion that they capture most of the possible conversational flows while pretending to be both an user and a bot.
For as long as I can remember, email has been a fundamentally important channel for a large majority of businesses. The ability to market products directly through a channel that scales up to an incredibly high ceiling is very attractive. The only problem is that it's costing more and more money to acquire email addresses from potential customers, and the engagement from email is getting worse and worse.

In so many ways I think chatbots are only just getting started – their potential is much underestimated at present. A big challenge is for chatbots mature so that they do more than is possible as a result of content entry wizards. If your content is created with a few easy clicks, it is unlikely to be much inspiration to anyone – and to date, despite much work in the field, the ability to emulated the creative open ended nature of real intellingence has seen only very partial success.
Yes, witty banter is a plus. But, the ultimate mission of a bot is to provide a service people actually want to use. As long as you think of your bot as just another communication channel, your focus will be misguided. The best bots harness the micro-decisions consumers experience on a daily basis and see them as an opportunity to help. Whether it's adjusting a reservation, updating the shipping info for an order, or giving medical advice, bots provide a solution when people need it most.
“They’re doing things we’re simply not doing in the U.S. Imagine if you were going to start a city from scratch. Rather than having to deal with all the infrastructure created 200 years ago, you could hit the ground running on the latest technology. That’s what China’s doing — they’re accessing markets for the first time through mobile apps and payments.” — Brian Buchwald, CEO of consumer intelligence firm Bomoda
Human touch. Chatbots, providing an interface similar to human-to-human interaction, are more intuitive and so less difficult to use than a standard banking mobile application. They doesn't require any additional software installation and are more adaptive as able to be personalized during the exploitation by the means of machine learning. Chatbots are instant and so much faster that phone calls, shown to be considered as tedious in some studies. Then they satisfy both speed and personalization requirement while interacting with a bank.

The term "ChatterBot" was originally coined by Michael Mauldin (creator of the first Verbot, Julia) in 1994 to describe these conversational programs.[2] Today, most chatbots are accessed via virtual assistants such as Google Assistant and Amazon Alexa, via messaging apps such as Facebook Messenger or WeChat, or via individual organizations' apps and websites.[3][4] Chatbots can be classified into usage categories such as conversational commerce (e-commerce via chat), analytics, communication, customer support, design, developer tools, education, entertainment, finance, food, games, health, HR, marketing, news, personal, productivity, shopping, social, sports, travel and utilities.[5]