The interview board assesses candidates during the UPSC interview through various methodologies. They evaluate a candidate's intellectual competence, personality traits, and suitability for a career in civil services. Questions often probe into a candidate's background, current affairs knowledge, and ethical decision-making abilities. The board looks for attributes like leadership, integrity, and interpersonal skills, as these are vital for public administration roles. Additionally, candidates' responses are scrutinized for clarity, confidence, and critical thinking, helping the board gauge their overall potential for effective service delivery.