At a high level, a conversational bot can be divided into the bot functionality (the "brain") and a set of surrounding requirements (the "body"). The brain includes the domain-aware components, including the bot logic and ML capabilities. Other components are domain agnostic and address non-functional requirements such as CI/CD, quality assurance, and security.

What if you’re creating a bot for a major online clothing retailer? For starters, the bot will require a greeting (“How can I help you?”) as well as a process for saying its goodbyes. In between, the bot needs to respond to inputs, which could range from shopping inquiries to questions about shipping rates or return policies, and the bot must possess a script for fielding questions it doesn’t understand.
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:

Chatbots currently operate through a number of channels, including web, within apps, and on messaging platforms. They also work across the spectrum from digital commerce to banking using bots for research, lead generation, and brand awareness. An increasing amount of businesses are experimenting with chatbots for e-commerce, customer service, and content delivery.
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.
Consumers really don’t like your chatbot. It’s not exactly a relationship built to last — a few clicks here, a few sentences there — but Forrester Analytics data shows us very clearly that, to consumers, your chatbot isn’t exactly “swipe right” material. That’s unfortunate, because using a chatbot for customer service can be incredibly effective when done […]
The plugin aspect to Chatfuel is one of the real bonuses. You can link up to all sorts of different services to add richer content to the conversations that you're having. This includes linking up to Twitter, Instagram and YouTube, as well as being able to request that the user share their location, serve video and audio content, and build out custom attributes that can be used to segment users based on their inputs. This last part is a killer feature.
This is where most applications of NLP struggle, and not just chatbots. Any system or application that relies upon a machine’s ability to parse human speech is likely to struggle with the complexities inherent in elements of speech such as metaphors and similes. Despite these considerable limitations, chatbots are becoming increasingly sophisticated, responsive, and more “natural.”
A very common request that we get is people want to practice conversation, said Duolingo's co-founder and CEO, Luis von Ahn. The company originally tried pairing up non-native speakers with native speakers for practice sessions, but according to von Ahn, "about three-quarters of the people we try it with are very embarrassed to speak in a foreign language with another person."
Haptik is one of the world's largest Conversational AI platforms reaching over 30 million devices monthly. The company has been at the forefront of the paradigm shift from apps to chatbots, having built a robust set of technology and tools that enable any type of conversational application. Our platform processed over a billion interactions to date and helps enterprises leverage the power of AI to automate critical business processes like Concierge, Customer Support, Lead Generation and E-commerce.
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.
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!
Botsify is another Facebook chatbot platform that helps make it easy to integrate chatbots into the system. Its paid subscription helps you in five easy steps. 1) Log into the site, 2) Connect your Facebook account, 3) Setup a webhook, 4) Write up commands for the chatbot you are creating, and 5) Let Botisfy handle the customer service for you. If the paid services are a little too much, they do offer a free service that lets you create as many bots as your lovely imagination can dream up.
Regardless of which type of classifier is used, the end-result is a response. Like a music box, there can be additional “movements” associated with the machinery. A response can make use of external information (like weather, a sports score, a web lookup, etc.) but this isn’t specific to chatbots, it’s just additional code. A response may reference specific “parts of speech” in the sentence, for example: a proper noun. Also the response (for an intent) can use conditional logic to provide different responses depending on the “state” of the conversation, this can be a random selection (to insert some ‘natural’ feeling).
Artificial Intelligence is currently being deployed in customer service to both augment and replace human agents - with the primary goals of improving the customer experience and reducing human customer service costs. While the technology is not yet able to perform all the tasks a human customer service representative could, many consumer requests are very simple ask that sometimes be handled by current AI technologies without human input.

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?”
I argued that it is super hard to scale a one-trick TODA into a general assistant that helps the user getting things done across multiple tasks. An intelligence assistant is arguably expected to hold an informal chit-chat with the user. It is this area where we are staring into perhaps the biggest challenge of AI. Observe how Samantha introduces herself to Joaquin Phoenix’s Ted in the clip below:
2. Flow-based: these work on user interaction with buttons and text. If you have used Matthew’s chatbot, that is a flow-based chatbot. The chatbot asks a question then offers options in the form of buttons (Matthew’s has a yes/no option). These are more limited, but you get the possibility of really driving down the conversation and making sure your users don’t stray off the path.
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.
Founded by Pavel Durov, creator of Russia’s equivalent to Facebook, Telegram launched in 2013 as a lightweight messaging app to combine the speed of WhatsApp with the ephemerality of Snapchat along with claimed enhanced privacy and security through its use of the MTProto protocol (Telegram has offered a $200k prize to any developer who can crack MTProto’s security). Telegram has 100M MAUs, putting it in the second tier of messaging apps in terms of popularity.

From any point in the conversation, the bot needs to know where to go next. If a user writes, “I’m looking for new pants,” the bot might ask, “For a man or woman?” The user may type, “For a woman.” Does the bot then ask about size, style, brand, or color? What if one of those modifiers was already specified in the query? The possibilities are endless, and every one of them has to be mapped with rules.
Founded by Pavel Durov, creator of Russia’s equivalent to Facebook, Telegram launched in 2013 as a lightweight messaging app to combine the speed of WhatsApp with the ephemerality of Snapchat along with claimed enhanced privacy and security through its use of the MTProto protocol (Telegram has offered a $200k prize to any developer who can crack MTProto’s security). Telegram has 100M MAUs, putting it in the second tier of messaging apps in terms of popularity.

The classification score produced identifies the class with the highest term matches (accounting for commonality of words) but this has limitations. A score is not the same as a probability, a score tells us which intent is most like the sentence but not the likelihood of it being a match. Thus it is difficult to apply a threshold for which classification scores to accept or not. Having the highest score from this type of algorithm only provides a relative basis, it may still be an inherently weak classification. Also the algorithm doesn’t account for what a sentence is not, it only counts what it is like. You might say this approach doesn’t consider what makes a sentence not a given class.
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).
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.
“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

In a traditional application, the user interface (UI) consists of a series of screens, and a single app or website can use one or more screens as needed to exchange information with the user. Most applications start with a main screen where users initially land, and that screen provides navigation that leads to other screens for various functions like starting a new order, browsing products, or looking for help.

We then ran a second test with a very specific topic aimed at answering very specific questions that a small segment of their audience was interested in. There, the engagement was much higher (97% open rate, 52% click-through rate on average over the duration of the test). Interestingly, drop-off went wayyy down there. At the end of this test, only 0.29% of the users had unsubscribed.

Companies and customers can benefit from internet bots. Internet bots are allowing customers to communicate with companies without having to communicate with a person. KLM Royal Dutch Airlines has produced a chatbot that allows customers to receive boarding passes, check in reminders, and other information that is needed for a flight.[10] Companies have made chatbots that can benefit customers. Customer engagement has grown since these chatbots have been developed.
How far are we from building systems with commonsense? One often-heard answer is: not in the near future, while the realistic answer is: we don’t know. Last year, I spent some time trying to build a system that can do better than an information retrieval baseline in taking fourth-grade science exam (which still has a ways to go to gain a passing score of 65%). I failed hard. Here’s an example to get a sense of the difficulty of these questions.
How: instead of asking someone to fill out a form on your website to be contacted by your sales team, you direct them straight into Messenger, where you can ask them some of their contact details and any qualification questions (for example, "How many employees does your company have?"). Depending on what they respond with you could ask if they'd like to arrange a meeting with a salesperson right there and then.

In a traditional application, the user interface (UI) is a series of screens. A single app or website can use one or more screens as needed to exchange information with the user. Most applications start with a main screen where users initially land and provide navigation that leads to other screens for various functions like starting a new order, browsing products, or looking for help.

The goal of intent-based bots is to solve user queries on a one to one basis. With each question answered it can adapt to the user behavior. The more data the bots receive, the more intelligent they become. Great examples of intent-based bots are Siri, Google Assistant, and Amazon Alexa. The bot has the ability to extract contextual information such as location, and state information like chat history, to suggest appropriate solutions in a specific situation.
How: this involves creating a basic content block within Chatfuel that has a discount code within it. Instead of giving all users of the bot the same experience, you can direct them through to specific parts of the conversation (or 'blocks'). Using the direct link to your content block, you'll be able to create CTAs on your website that direct people straight into Messenger to get a discount code (more info here).
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. 
The Evie chatbot has had a huge impact on social media over the last few years. She is probably the most popular artificial personality on YouTube. She has appeared in several videos by PewdiePie, the most subscribed YouTuber in the world. This includes a flirting video with over 12 million views! Evie has been filmed speaking many different languages. She chats with Squeezie in French, El Rubius and El Rincón De Giorgio in Spanish, GermanLetsPlay and ConCrafter in German, NDNG - Enes Batur in Turkish, Stuu Games in Polish and jacksepticeye, ComedyShortsGamer and KSIOlajidebtHD in English. And that is a very small selection. Evie shares her database with Cleverbot, which is an internet star in its own right. Cleverbot conversations have long been shared on Twitter, Facebook, websites, forums and bulletin boards. We are currently working to give Evie some more artificial companions, such as the male avatar Boibot.
Nowadays a high majority of high-tech banking organizations are looking for integration of automated AI-based solutions such as chatbots in their customer service in order to provide faster and cheaper assistance to their clients becoming increasingly technodexterous. In particularly, chatbots can efficiently conduct a dialogue, usually substituting other communication tools such as email, phone, or SMS. In banking area their major application is related to quick customer service answering common requests, and transactional support.