Motivational Interviewing (MI) is a collaborative communication method used to strengthen a person's motivation to change. It works by exploring their own reasons for change through open-ended questions, affirmations of progress, reflective listening, and summaries of discussion. The core MI skills are open-ended questions, affirmations, reflections, and summaries. MI principles include expressing empathy, supporting self-efficacy, avoiding argumentation, accepting resistance, and developing discrepancy between goals and behavior.