  Building conversational agents have many technical, design and linguistic
challenges. Other more complex elements include using emotionally intelligent
conversational agent to build trust with the individuals. In this chapter, we
introduce the nature of conversational user interfaces (CUIs) for health and
describe UX design principles informed by a systematic literature review of
relevant research works. We analyze scientific literature in conversational
interfaces and chatterbots, providing a survey of major studies and describing
UX design principles and interaction patterns.
