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.
Message generator component consists of several user defined templates (templates are nothing but sentences with some placeholders, as appropriate) that map to the action names. So depending on the action predicted by the dialogue manager, the respective template message is invoked. If the template requires some placeholder values to be filled up, those values are also passed by the dialogue manager to the generator. Then the appropriate message is displayed to the user and the bot goes into a wait mode listening for the user input.
Three main reasons are often cited for this reluctance: the first is the human side—they think users will be reluctant to engage with a bot. The other two have more to do with bots’ expected performance: there is skepticism that bots will be able to appropriately incorporate history and context to create personalized experiences and believe they won’t be able to adequately understand human input.
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:
Consider why someone would turn to a bot in the first place. According to an upcoming HubSpot research report, of the 71% of people willing to use messaging apps to get customer assistance, many do it because they want their problem solved, fast. And if you've ever used (or possibly profaned) Siri, you know there's a much lower tolerance for machines to make mistakes.
Despite the fact that ALICE relies on such an old codebase, the bot offers users a remarkably accurate conversational experience. Of course, no bot is perfect, especially one that’s old enough to legally drink in the U.S. if only it had a physical form. ALICE, like many contemporary bots, struggles with the nuances of some questions and returns a mixture of inadvertently postmodern answers and statements that suggest ALICE has greater self-awareness for which we might give the agent credit.

It's fair to say that I'm pretty obsessed with chatbots right now. There are some great applications popping up from brands that genuinely add value to the end consumer, and early signs are showing that consumers are actually responding really well to them. For those of you who aren't quite sure what I'm talking about, here's a quick overview of what a chatbot is:
As retrieved from Forbes, Salesforce’s chief scientist, Richard Socher talked in a conference about his revelations of NLP and machine translation: “I can’t speak for all chatbot deployments in the world – there are some that aren’t done very well…but in our case we’ve heard very positive feedback because when a bot correctly answers questions or fills your requirements it does it very, very fast.
Chatbots are unique because they not only engage with your customers, they also retain them. This means that unlike other forms of marketing, chatbots keep your customers entertained for longer. For example, let's say you catch your audience's attention with a video. While this video may be extremely engaging, once it ends, it doesn't have much more to offer.
This machine learning algorithm, known as neural networks, consists of different layers for analyzing and learning data. Inspired by the human brain, each layer is consists of its own artificial neurons that are interconnected and responsive to one another. Each connection is weighted by previous learning patterns or events and with each input of data, more "learning" takes place.
Kik Messenger, which has 275 million registered users, recently announced a bot store. This includes one bot to send people Vine videos and another for getting makeup suggestions from Sephora. Twitter has had bots for years, like this bot that tweets about earthquakes as soon as they’re registered or a Domino’s bot that allows you to order a pizza by tweeting a pizza emoji.

It may be tempting to assume that users will perform procedural tasks one by one in a neat and orderly way. For example, in a procedural conversation flow using dialogs, the user will start at root dialog, invoke the new order dialog from there, and then invoke the product search dialog. Then the user will select a product and confirm, exiting the product search dialog, complete the order, exiting the new order dialog, and arrive back at the root dialog.
Kunze recognises that chatbots are the vogue subject right now, saying: “We are in a hype cycle, and rising tides from entrants like Microsoft and Facebook have raised all ships. Pandorabots typically adds up to 2,000 developers monthly. In the past few weeks, we've seen a 275 percent spike in sign-ups, and an influx of interest from big, big brands.”
“Utility gets something done following a prompt. At a higher level the more entertainment-related chatbots are able to answer all questions and get things done. Siri and Cortana you can have small talk with, as well as getting things done, so they are much harder to build. They took years and years of giant company’s efforts. Different companies that don’t have those resources, like Facebook, will build more constrained utility bots.”

If a text-sending algorithm can pass itself off as a human instead of a chatbot, its message would be more credible. Therefore, human-seeming chatbots with well-crafted online identities could start scattering fake news that seem plausible, for instance making false claims during a presidential election. With enough chatbots, it might be even possible to achieve artificial social proof.[58][59]
There are a bunch of e-commerce stores taking advantage of chatbots as well. One example that I was playing with was from Fynd that enables you to ask for specific products and they'll display them to you directly within Messenger. What's more, Facebook even allows you to make payments via Messenger bots, opening up a whole world of possibility to e-commerce stores.
A chatbot is an automated program that interacts with customers like a human would and cost little to nothing to engage with. Chatbots attend to customers at all times of the day and week and are not limited by time or a physical location. This makes its implementation appealing to a lot of businesses that may not have the man-power or financial resources to keep employees working around the clock.
Indeed, this is one of the key benefits of chatbots – providing a 24/7/365 presence that can give prospects and customers access to information no matter when they need it. This, in turn, can result in cost-savings for companies that deploy chatbots, as they cut down on the labour-hours that would be required for staff to manage a direct messaging service every hour of the week.
Have you checked out Facebook Messenger’s official page lately? Well, now you can start building your own bot directly through the platform’s landing page. This method though, may be a little bit more complicated than some of the previous ways we’ve discussed, but there are a lot of resources that Facebook Messenger provides in order to help you accomplish your brand new creation. Through full-fledged guides, case studies, a forum for Facebook developers, and more, you are sure to be a chatbot creating professional in no time.
Es gibt auch Chatbots, die gar nicht erst versuchen, wie ein menschlicher Chatter zu wirken (daher keine Chatterbots), sondern ähnlich wie IRC-Dienste nur auf spezielle Befehle reagieren. Sie können als Schnittstelle zu Diensten außerhalb des Chats dienen, oder auch Funktionen nur innerhalb ihres Chatraums anbieten, z. B. neu hinzugekommene Chatter mit dem Witz des Tages begrüßen.
Enter Roof Ai, a chatbot that helps real-estate marketers to automate interacting with potential leads and lead assignment via social media. The bot identifies potential leads via Facebook, then responds almost instantaneously in a friendly, helpful, and conversational tone that closely resembles that of a real person. Based on user input, Roof Ai prompts potential leads to provide a little more information, before automatically assigning the lead to a sales agent.

Intents: It is basically the action chatbot should perform when the user say something. For instance, intent can trigger same thing if user types “I want to order a red pair of shoes”, “Do you have red shoes? I want to order them” or “Show me some red pair of shoes”, all of these user’s text show trigger single command giving users options for Red pair of shoes.
According to the Journal of Medical Internet Research, "Chatbots are [...] increasingly used in particular for mental health applications, prevention and behavior change applications (such as smoking cessation or physical activity interventions).".[48] They have been shown to serve as a cost-effective and accessible therapeutic agents for indications such as depression and anxiety.[49] A conversational agent called Woebot has been shown to significantly reduce depression in young adults.[50]