Remote access laboratories are increasingly being integrated into undergraduate engineering curricula on a global scale. Despite the vast body of literature dealing with remotely-accessible laboratories, the majority of papers have focused on the technical merits of a particular implementation, rather than on the implications of remote access experimentation on engineering pedagogy. Recently, a few studies have attempted to quantify the effects of the remote access modality on students' learning outcomes. These initial pedagogical studies have indicated that there is indeed a difference between proximal and remote experimentation in terms of learning outcomes. However, the question still unanswered is if these observed differences are a result of the physical separation between student and hardware, or rather are a result of the computermediated interface used to control the remote hardware. This paper discusses the results of a comprehensive study comparing the pedagogical effects of remote vs. proximal experimentation that includes control over the effects of the computer-mediated interface. Two groups of students performed the same experiment proximally and remotely using the same computer interface, and the learning outcomes are examined. © American Society for Engineering Education, 2009.