This study introduces a tool that visualizes text-based content in online discussion forums, focusing on social interactions and topic relationships. By leveraging weak ties theory, the tool helps to reveal the connections between topics and student interactions, and to identify how serendipitous learning opportunities emerge. The tool’s implementation showed that major topics were strongly related to course outcomes, while weaker connections provided insights into unexpected learning. This approach could enhance the learning and teaching process, benefiting formative assessment design and collaborative learning.