Although several studies related to social-context awareness (SA) and knowledge-context awareness (KA) argued that each (SA or KA) can individually enhance peer interaction in an online learning community, other studies reached opposite conclusions. These conflicting findings likely stem from different experimental settings. Most importantly, few studies have investigated the difference between the impacts of SA and KA under an identical experimental setting, which can be used to determine whether SA or KA better enhances peer collaboration. Restated, direct empirical comparisons of these two approaches are lacking. This work simultaneously investigates the impacts of SA and KA on quantitative and qualitative peer interaction and learning performance using the same experimental setting. Additionally, an underlying repeated-measurement design is applied to investigate peer interaction patterns and learning performance in SA and KA communities. Experimental results show that SA can stimulate more quantitative peer interaction than KA. However, both SA and KA have limited capacity to elicit qualified message content, even in a longitudinal experiment. Although the scores of SA and KA communities did not differ significantly on the first posttest, the SA community had significantly better learning performance on the second posttest, likely related to more extensive and frequent interaction among peers within the SA community.