Judy Diamond is professor and curator of informal science education at the University of Nebraska State Museum. A biologist and science educator, she is the author of over 40 publications on informal learning. She has a long career working in science museums, first as curriculum developer at the Lawrence Hall of Science, as evaluator and project coordinator at the Exploratorium, and as deputy director for public programs at the San Diego Natural History Museum. Michael Stephen Horn is assistant professor of learning sciences and computer science at Northwestern University where he directs the Tangible Interaction Design and Learning Lab. Horn earned a PhD in Human Computer Interaction from Tufts University in 2009 and has been developing innovative technology-based learning experiences for museum and other informal learning environments for over ten year. His research interests involve understanding the role of cultural forms in shaping participating and learning around physical and technological artifacts. He is the author of over 30 scholarly articles and his work can be seen at the Museum of Science, Boston, the California Academy of Sciences, the Field Museum, and the Computer History Museum. David H. Uttal is professor of psychology and education at Northwestern University. He holds a doctorate in developmental psychology from the University of Michigan, and he is the author of over 50 articles and book chapters. His research interests are in the development of children’s thinking, with a focus on symbolic and spatial reasoning, and his work has been supported by the National Institutes of Health, the National Science Foundation, and the Institute of Education Sciences. At Northwestern he directs the multidisciplinary program in education sciences, which trains graduate students from different disciplines to conduct rigorous research in educational contexts.