"Vicarious learning" research is a burgeoning area of inquiry, which examines the learning of students who observe and are engaged with video- or audio-taped presentations of other people engaged in learning (Chi et al., 2008). In such studies, the students or "vicarious learners" (VLs) are positioned as indirect participants in a dialogue featured in the video- or audiorecording. Several projects have identified features of dialogic videos that benefit VLs. However, an important question remains: Does the nature of the dialogue--whether it is scripted or unscripted--matter? For this study, I created two sets of dialogic videos, one featuring the unscripted dialogue of two precalculus students and the other featuring a scripted dialogue between a teacher (myself) and a precalculus student. These videos capture the inquiry process of the direct participants (i.e., the talent) engaged in a task sequence emphasizing covariational reasoning and culminated in the construction of the sine function. Four pairs of VLs were assigned to view either unscripted or scripted videos over five research sessions. This study posed two research questions that explored differences across the treatments: one about how the VLs oriented toward the talent, and the second about the problem-solving behaviors of the VLs. To answer the first question, I analyzed the data qualitatively, using a priori and inductive codes. To answer the second question, I conducted thematic analysis, as described by Braun and Clarke (2004). Results indicated that the VLs viewing unscripted dialogic videos consistently evidenced an emotionally-involved quasi-collaborative orientation toward the talent, (i.e., they acted "as if" they were in a collaborative group with the talent) with regular displays of emotion (e.g., surprise). In contrast, the VLs viewing the scripted videos evidenced a cognitively- and emotionally-distanced orientation toward the talent. Thematic analysis revealed a difference in the pairs' problem-solving behavior across three themes: (a) "patterns of" [video] "use," (b) "idea justification," and (c) "idea management." For example, the VLs viewing unscripted videos frequently negotiated with ideas from the talent. In contrast, the VLs viewing scripted videos frequently repeated a solution from the talent without attending to the underlying mathematical meaning. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]