An OSMO reference document hosted on edCircuit with permission from Osmo. Written by: Heidy Maldonado, Tangible Play, heidy@tangibleplay.comAriel Zekelman, Tangible Play, ariel@tangibleplay.com Abstract: Inspired by Fröbel and Montessori manipulatives, we followed Design-Based Research methods in the creation of a tangible letter learning game for three- through five-year old children. In this paper we cover the iterative design and evaluation cycles, and the constraints and tradeoffs explored across implementations, as the game evolved from Alpha to Beta phases. We incorporate explicit feedback and analytics of play data from the Beta experience of two-hundred seventy-three children across two different contexts (school andhome) to discuss current design concerns, future work, and possible implications.Introduction Children’s letter knowledge is the foundation of literacy. The alphabetic principle is the understanding that there are systematic and prescriptive relationships between written letters and spoken sounds. Given its importance asthe first step towards academic achievement and attainment, neuroscientist Dehaene …