Simple chatbots, or bots, are easy to build. In fact, many coders have automated bot-building processes and templates. The majority of these processes follow simple code formulas that the designer plans, and the bots provide the responses coded into it—and only those responses. Simplistic bots (built in five minutes or less) typically respond to one or two very specific commands.
Whilst the payout wasn't huge within the early days of Amazon, those who got in early are now seeing huge rewards, with 38% of shoppers starting their buying journey within Amazon (source), making it the number one retail search engine. Some studies are suggesting that Amazon is responsible for 80% of e-commerce growth for publicly traded web retailers (source).

Simply put, chatbots are computer programs designed to have conversations with human users. Chances are you’ve interacted with one. They answer questions, guide you through a purchase, provide technical support, and can even teach you a new language. You can find them on devices, websites, text messages, and messaging apps—in other words, they’re everywhere.
Context: When a NLU algorithm analyzes a sentence, it does not have the history of the user conversation. It means that if it receives the answer to a question it has just asked, it will not remember the question. For differentiating the phases during the chat conversation, it’s state should be stored. It can either be flags like “Ordering Pizza” or parameters like “Restaurant: ‘Dominos’”. With context, you can easily relate intents with no need to know what was the previous question.
ELIZA's key method of operation (copied by chatbot designers ever since) involves the recognition of clue words or phrases in the input, and the output of corresponding pre-prepared or pre-programmed responses that can move the conversation forward in an apparently meaningful way (e.g. by responding to any input that contains the word 'MOTHER' with 'TELL ME MORE ABOUT YOUR FAMILY').[9] Thus an illusion of understanding is generated, even though the processing involved has been merely superficial. ELIZA showed that such an illusion is surprisingly easy to generate, because human judges are so ready to give the benefit of the doubt when conversational responses are capable of being interpreted as "intelligent".
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