This NSF IUSE:EDU Level 1 project aims to serve the national interest by developing design principles by which educational tools powered by generative AI can support the goal of personalized learning in STEM education. Generative AI models, such as large language models, have presented educators with a tangible step toward addressing the National Academies of Engineering's grand challenge of personalized learning. In particular, chatbot-style AI tools (e.g., ChatGPT) have gained significant attention as mechanisms to enhance learning environments within and outside the classroom. Much effort has been placed into developing specific chatbots for disciplinary contexts, which lean heavily on the purported problem-solving abilities of modern large language models. This project plans to question design processes when creating these systems and aims to develop and test design principles for developing AI-empowered educational tools, focusing on providing personalized and humanized interactions and feedback grounded in theories of social presence and self-regulated learning. Computational thinking is recognized as a core 21st-century skill and a vital part of STEM education. As a context for testing the design principles, the project team intends to focus on courses aimed at developing computational thinking. The project team plans to build a generative AI tool called the "coachbot" utilizing the proposed education-informed design principles and will be tested in two complementary