Natural Language Processing (NLP) is the technological process in which computers derive meaning from natural human inputs. NLP-Based Conversational Bots are machine learning bots that exploit the power of artificial intelligence, which gives them a “learning brain.” These types of conversational bots have the ability to understand natural language, and do not require specific instructions to respond to questions as observed in types of chatbots such as Scripted and Structured Conversational Bots.
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.
As AOL's David Shingy writes in Adweek, "The challenge [with chatbots] will be thinking about creative from a whole different view: Can we have creative that scales? That customizes itself? We find ourselves hurtling toward another handoff from man to machine -- what larger system of creative or complex storytelling structure can I design such that a machine can use it appropriately and effectively?"
The bot (which also offers users the opportunity to chat with your friendly neighborhood Spiderman) isn’t a true conversational agent, in the sense that the bot’s responses are currently a little limited; this isn’t a truly “freestyle” chatbot. For example, in the conversation above, the bot didn’t recognize the reply as a valid response – kind of a bummer if you’re hoping for an immersive experience.

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.

There is no one right answer to this question, as the best solution will depend upon the specifics of your scenario and how the user would reasonably expect the bot to respond. However, as your conversation complexity increases dialogs become harder to manage. For complex branchings situations, it may be easier to create your own flow of control logic to keep track of your user's conversation.

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.