This paper focuses on the impact of relevant backgrounds on computer-mediated knowledge sharing and individual knowledge acquisition. An experiment is described based on the coherence principle from the Cognitive Theory of Multi-Media Learning. Results suggest groups using visual chat scored higher in retention and understanding than individuals working alone. In addition, participants using visual chat with relevant backgrounds obtained higher levels of understanding than participants using no relevance or irrelevant backgrounds. These results support the coherence principle in the cognitive theory of multimedia learning and suggest new directions in the design and evaluation of knowledge sharing environments.