Collaborative intellectual engagement is held in high regard in contemporary educational thought as a pedagogical practice of broad value to K-12 students. To what extent is this enthusiasm warranted? Is the practice uniformly productive, or does variability exist in the contexts in which collaboration is effective, the mechanisms involved, and the objectives achieved? In addition to examining these questions, this article suggests further questions that might be addressed with the objective of establishing a more comprehensive base of evidence to substantiate the practice of collaborative learning. Finally, the article reconsiders why collaborative cognition should be a critical concern.