Understanding knowledge transfer using computer-mediated context is becoming essential given that organizations are spread more and more globally. In this paper, we adopt elaboration likelihood theory to investigate knowledge transfer processes in a Knowledge Management System (KMS). We report the results of an exploratory experiment conducted to examine the impact of argument quality, source credibility and validation on knowledge usefulness of a document in a KMS. Our findings indicate that while validation of knowledge in KMS positively affects perceptions of knowledge usefulness, higher argument quality was associated with lower usefulness ratings. Surprisingly, source credibility has no effect on perceptions of knowledge usefulness. The implications of these results for both researchers and practitioners are discussed.