Dr. Contrarian: a persona-driven conversational AI agent for coaching argumentative reasoning in infectious disease classroom debates.

Critical thinking and persuasive communication are essential for biology graduates navigating socioscientific dilemmas. While debate pedagogy fosters problem-solving, autonomy, competence, and relatedness aligned with adult learning and self-determination theories, inexperienced students often struggle with the cognitive load and anxiety from this format. To bridge this gap, "Dr. Contrarian," a persona-based conversational AI agent, was developed to function as an adversarial coach during debate preparation. Survey data (n = 21) adapted from the Technology Acceptance Model show that 85.7% of students found the tool easy to use, and 71.4% would use it again. Thematic analysis of metacognitive reflections suggests that while Dr. Contrarian facilitated meaningful cognitive engagement, spontaneous live rebuttals remain challenging for most students. Ultimately, by serving as a low-stakes ideological sandbox, this instructor-designed AI tool overcomes pedagogical barriers faced by novice debaters, allowing students to fully engage in and benefit from classroom debates.