The phrase "compared notes" implies a process of sharing, comparing, and discussing information. Antonyms for this phrase could include "withheld information," "kept secrets," "worked alone," or "operated in silos." These antonyms suggest a lack of collaboration, transparency or communication in the exchange of information. In contrast, "compared notes" encourages teamwork, mutual trust and respect among individuals or groups. The phrase is often used in educational, legal, or scientific contexts to ensure accuracy, thoroughness, and objectivity in the analysis of data. Overall, the antonyms for "compared notes" underscore the importance of open and honest dialogue, active listening, and collaboration for achieving shared goals and objectives.