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'). 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".
Creating a comprehensive conversational flow chart will feel like the greatest hurdle of the process, but know it's just the beginning. It's the commitment to tweaking and improving in the months and years following that makes a great bot. As Clara de Soto, cofounder of Reply.ai, told VentureBeat, "You're never just 'building a bot' so much as launching a 'conversational strategy' — one that's constantly evolving and being optimized based on how users are actually interacting with it."