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.
Previous generations of chatbots were present on company websites, e.g. Ask Jenn from Alaska Airlines which debuted in 2008 or Expedia's virtual customer service agent which launched in 2011.  The newer generation of chatbots includes IBM Watson-powered "Rocky", introduced in February 2017 by the New York City-based e-commerce company Rare Carat to provide information to prospective diamond buyers. 
As IBM elaborates: “The front-end app you develop will interact with an AI application. That AI application — usually a hosted service — is the component that interprets user data, directs the flow of the conversation and gathers the information needed for responses. You can then implement the business logic and any other components needed to enable conversations and deliver results.”
There are various search engines for bots, such as Chatbottle, Botlist and Thereisabotforthat, for example, helping developers to inform users about the launch of new talkbots. These sites also provide a ranking of bots by various parameters: the number of votes, user statistics, platforms, categories (travel, productivity, social interaction, e-commerce, entertainment, news, etc.). They feature more than three and a half thousand bots for Facebook Messenger, Slack, Skype and Kik.
More and more businesses are choosing AI chatbots as part of their customer service team. There are several reasons for that. Chatbots can answer customers’ inquiries cheaply, quickly, in real-time. Another reason is the ease of installation of such chatbot: once you have a fine live chat app, it takes a couple of minutes to integrate a chatbot with it.
ALICE – which stands for Artificial Linguistic Internet Computer Entity, an acronym that could have been lifted straight out of an episode of The X-Files – was developed and launched by creator Dr. Richard Wallace way back in the dark days of the early Internet in 1995. (As you can see in the image above, the website’s aesthetic remains virtually unchanged since that time, a powerful reminder of how far web design has come.)
Prashant Sridharan, Twitter’s global director of developer relations says: “I’ve seen a lot of hyperbole around bots as the new apps, but I don’t know if I believe that. I don’t think we’re going to see this mass exodus of people stopping building apps and going to build bots. I think they’re going to build bots in addition to the app that they have or the service they provide,” as reported by re/code.
Lack contextual awareness. Not everyone has all of the data that Google has – but chatbots today lack the awareness that we expect them to have. We assume that chatbot technology will know our IP address, browsing history, previous purchases, but that is just not the case today. I would argue that many chatbots even lack basic connection to other data silos to improve their ability to answer questions.
This importance is reinforced by Jacqueline Payne, Customer Support Manager at Paperclip Digital, who says ‘Customer service isn’t a buzzword. But too many businesses treat it like it is. As a viable avenue from which to lower customer acquisition costs and cultivate a loyal customer base, chat bots can play a pivotal role in driving business growth.’
Most chatbots try to mimic human interactions, which can frustrate users when a misunderstanding arises. Watson Assistant is more. It knows when to search for an answer from a knowledge base, when to ask for clarity, and when to direct you to a human. Watson Assistant can run on any cloud – allowing businesses to bring AI to their data and apps wherever they are.
Dialogflow is a very robust platform for developing chatbots. One of the strongest reasons of using Dialogflow is its powerful Natural Language Understanding (NLU). You can build highly interactive chatbot as NLP of Dialogflow excels in intent classification and entity detection. It also offers integration with many chat platforms like Google Assistant, Facebook Messenger, Telegram,…
What began as a televised ad campaign eventually became a fully interactive chatbot developed for PG Tips’ parent company, Unilever (which also happens to own an alarming number of the most commonly known household brands) by London-based agency Ubisend, which specializes in developing bespoke chatbot applications for brands. The aim of the bot was to not only raise brand awareness for PG Tips tea, but also to raise funds for Red Nose Day through the 1 Million Laughs campaign.
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:
Several studies accomplished by analytics agencies such as Juniper or Gartner  report significant reduction of cost of customer services, leading to billions of dollars of economy in the next 10 years. Gartner predicts an integration by 2020 of chatbots in at least 85% of all client's applications to customer service. Juniper's study announces an impressive amount of $8 billion retained annually by 2022 due to the use of chatbots.