Multinational Naive Bayes is the classic algorithm for text classification and NLP. For an instance, let’s assume a set of sentences are given which are belonging to a particular class. With new input sentence, each word is counted for its occurrence and is accounted for its commonality and each class is assigned a score. The highest scored class is the most likely to be associated with the input sentence.
But, as any human knows, no question or statement in a conversation really has a limited number of potential responses. There is an infinite number of ways to combine the finite number of words in a human language to say something. Real conversation requires creativity, spontaneity, and inference. Right now, those traits are still the realm of humans alone. There is still a gamut of work to finish in order to make bots as person-centric as Rogerian therapists, but bots and their creators are getting closer every day.
When you have a desperate need for a java fix with minimal human interaction and effort, this bot has you covered. According to a demo led by Gerri Martin-Flickinger, the coffee chain's chief technology officer, the bot even understands complex orders with special requests, like "double upside down macchiato half decaf with room and a splash of cream in a grande cup."
These days, checking the headlines over morning coffee is as much about figuring out if we should be hunkering down in the basement preparing for imminent nuclear annihilation as it is about keeping up with the day’s headlines. Unfortunately, even the most diligent newshounds may find it difficult to distinguish the signal from the noise, which is why NBC launched its NBC Politics Bot on Facebook Messenger shortly before the U.S. presidential election in 2016.
Amazon’s Echo device has been a surprise hit, reaching over 3M units sold in less than 18 months. Although part of this success can be attributed to the massive awareness-building power of the homepage, the device receives positive reviews from customers and experts alike, and has even prompted Google to develop its own version of the same device, Google Home.
Need a Facebook bot? Well, look no further, as Chatfuel makes it easy for you to create your own Facebook and Telegram Chatbot without any coding experience necessary. It works by letting users link to external sources through plugins. Eventually, the platforms hope to open itself to third-party plugins, so anyone can contribute their own plugins and have others benefit from them.
Facebook has jumped fully on the conversational commerce bandwagon and is betting big that it can turn its popular Messenger app into a business messaging powerhouse. The company first integrated peer-to-peer payments into Messenger in 2015, and then launched a full chatbot API so businesses can create interactions for customers to occur within the Facebook Messenger app. You can order flowers from 1–800-Flowers, browse the latest fashion and make purchases from Spring, and order an Uber, all from within a Messenger chat.
Improve loyalty: By providing a responsive, efficient experience for customers, employees and partners, a chatbot will improve satisfaction and loyalty. Whether your chatbot answers questions about employees’ corporate benefits or provides answers to technical support questions, users can come away with a strengthened connection to your organization.

The evolution of artificial intelligence is now in full swing and chatbots are only a faint splash on a huge wave of progress. Today the number of users of messaging apps like WhatsApp, Slack, Skype and their analogs is skyrocketing, Facebook Messenger alone has more than 1.2 billion monthly users. With the spread of messengers, virtual chatterbots that imitate human conversations for solving various tasks are becoming increasingly in demand. Chinese WeChat bots can already set medical appointments, call a taxi, send money to friends, check in for a flight and many many other.
“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
Chatbots have come a long way since then. They are built on AI technologies, including deep learning, natural language processing and  machine learning algorithms, and require massive amounts of data. The more an end user interacts with the bot, the better voice recognition becomes at predicting what the appropriate response is when communicating with an end user.

NBC Politics Bot allowed users to engage with the conversational agent via Facebook to identify breaking news topics that would be of interest to the network’s various audience demographics. After beginning the initial interaction, the bot provided users with customized news results (prioritizing video content, a move that undoubtedly made Facebook happy) based on their preferences.

Chatbots are predicted to be progressively present in businesses and will automate tasks that do not require skill-based talents. Companies are getting smarter with touchpoints and customer service now comes in the form of instant messenger, as well as phone calls. IBM recently predicted that 85% of customer service enquiries will be handled by AI as early as 2020.[62] The call centre workers may be particularly at risk from AI.[63]
[…] But how can simple code assimilate something as complex as speech in only the span of a handful of years? It took humans hundreds of generations to identify, compose and collate the English language. Chatbots have a one up on humans, because of the way they dissect the vast data given to them. Now that we have a grip on the basics, we’ll understand how chatbots work in the next series. […]
With our intuitive interface, you dont need any programming skills to create realistic and entertaining chatbots. Your chatbots live on the site and can chat independently with others. Transcripts of every chatbot's conversations are kept so you can read what your bot has said, and see their emotional relationships and memories. Best of all, it's free!
ETL. The bot relies on information and knowledge extracted from the raw data by an ETL process in the backend. This data might be structured (SQL database), semi-structured (CRM system, FAQs), or unstructured (Word documents, PDFs, web logs). An ETL subsystem extracts the data on a fixed schedule. The content is transformed and enriched, then loaded into an intermediary data store, such as Cosmos DB or Azure Blob Storage.
All of these conversational technologies employ natural-language-recognition capabilities to discern what the user is saying, and other sophisticated intelligence tools to determine what he or she truly needs to know. These technologies are beginning to use machine learning to learn from interactions and improve the resulting recommendations and responses.
Businesses are no exception to this rule. As more and more users now expect and prefer chat as a primary mode of communication, we’ll begin to see more and more businesses leveraging conversational AI to achieve business goals—just as Gartner predicts. It’s not just for the customer; your business can reduce operational costs and scale operations as well.
You may remember Facebook’s big chatbot push in 2016 –  when they announced that they were opening up the Messenger platform to chatbots of all varieties. Every organization suddenly needed to get their hands on the technology. The idea of having conversational chatbot technology was enthralling, but behind all the glitz, glamour and tech sex appeal, was something a little bit less exciting. To quote Gizmodo writer, Darren Orf:

Simple chatbots work based on pre-written keywords that they understand. Each of these commands must be written by the developer separately using regular expressions or other forms of string analysis. If the user has asked a question without using a single keyword, the robot can not understand it and, as a rule, responds with messages like “sorry, I did not understand”.

A chatbot (also known as a spy, conversational bot, chatterbot, interactive agent, conversational interface, Conversational AI, talkbot or artificial spy entity) is a computer program or an artificial intelligence which conducts a conversation via auditory or textual methods.[1] Such programs are often designed to convincingly simulate how a human would behave as a conversational partner, thereby passing the Turing test. Chatbots are typically used in dialog systems for various practical purposes including customer service or information acquisition. Some chatbots use sophisticated natural language processing systems, but many simpler ones scan for keywords within the input, then pull a reply with the most matching keywords, or the most similar wording pattern, from a database.