Unit 5 teaches students the technical foundations of natural language processing and puts them to work designing a real chatbot use case integrating all five Semester 1 units in a single culminating project. Students start with why language is hard for machines (ambiguity, sarcasm, cultural context), trace the five-stage NLP pipeline from raw text to prediction, and build toward understanding how large language models like ChatGPT and Claude work at a conceptual level. Week 2 covers where langua