We provide empirical support for the assertions that high level of knowledge construction is associated with structured design and that knowledge construction is associated with cohesion and equivalence network structures. We built and analyzed two CSCL communities - one structured the other non-structured. The levels of learning processes were measured by content analysis. The social capital structure of the communities was analyzed by Social Network Analysis. The analysis revealed that the structured community developed social capital, encoded by a mesh of interlinked cliques, and that participants undertook bridging and triggering roles, and exhibited high levels of constructing knowledge. The tutor (guide) remained on the side. The non-structured community did not construct knowledge, cohesion was dull, and participants did not undertake any essential roles.