A promising instructional approach corresponds to" learning by observing others learn" (i.e., by watching tutorial dialogue between a tutor and tutee). However, more work is needed to understand this approach's pedagogical utility. Thus, in 2 experiments we compared student learning from collaborative observation of dialogue with 2 other instructional contexts: 1-on-1 human tutoring and collaborative observation of monologue. In Study 1 (N = 50), there was no significant difference in learning outcomes between the dialogue and tutoring conditions, while the dialogue condition was superior to the monologue condition. Study 2 (N = 40), which involved a younger population than in Study 1, did not replicate these results, in that students learned less from observing dialogue than from being tutored, and there was no significant difference between the dialogue and monologue conditions. To shed light on our results, we analyzed the verbal data collected during the 2 experiments. This analysis showed that in Study 1, the dialogue observers generated more substantive contributions than did the monologue observers. In contrast, in Study 2 there was no significant difference between the observers in terms of substantive contributions; moreover, the total number of contributions was modest, which may have hindered observer learning in that study. In general, our findings suggest that collaboratively observing tutorial dialogue is a promising learning paradigm, but more work is needed to understand how to support young students to effectively learn in this paradigm.