Conference PaperBuilding Blocks: Kids Designing scientific, domain-specific, block- based, agent-based microworldsMartin, Kit; Bain, Connor; Swanson, Hillary; Horn, Michael; Wilensky, UriNext Generation Science Standards foreground science practices as important goals of science education. In this paper, we discuss the design of block-based modeling environments for learning experiences that ask students to actively explore complex systems via computer programming. Specifically, we discuss the implications of the design and selection of the types of blocks given to learners in these environments and how they may affect students’ thinking about the process of modeling and theorizing. We conclude with a discussion of some preliminary findings in this design based research to inform design principles for block-based programming of science phenomena as a medium for learning to build theory.2020-06-0110199201International Conference of the Learning Sciences (2020)Jun-20201641-1644https://doi.org/1842374; 1640201National Science Foundation