The field of instructional design and technology (IDT) aims to understand the interactions occurring among people and learning resources during educational experiences to inform design. This article illustrates the utility of mobile eye-tracking for research with children as a tool for IDT researchers and practitioners. Mobile eye-tracking can collect precise information concerning the learners' visual attention and interactions in authentic environments, unlike traditional eye-tracking using a laboratory or stationary computer. Mobile eye-tracking also can be used effectively in out-of-school settings where learners walk around and interact with diverse resources. By presenting a qualitative interaction analysis, we illuminate how mobile eye-tracking supports investigating explorations in a hands-on museum. The analysis shows patterns of visual and bodily interactions with exhibits and with family members. Implications include how mobile eye-tracking can contribute to a researcher's understanding of the child's idiosyncratic viewpoint to examine in detail learners' interactions and educational resources' affordances at various educational settings.