I explore how children engage in testing, tinkering, and sense making during play around topics or phenomena that they find personally engaging. In particular I study how children use intuitions about natural phenomena and scientific principles to interpret and assimilate central representations and tools found in play spaces, and how we might reconceive these environments to provide rich learning experiences that all children will see as highly connected to their personal values and goals as well as to formal tools and ideas. This work involves attending closely to the design of representations and tools within these play spaces as well as the artifacts (both tangible and intangible) constructed by children during play. My work is situated squarely in the constructionist tradition and often involves the design and creation of useful and powerful educational tools in the service of the refinement and development of cognitive theory. My current research explores play and learning in diverse contexts (such as makerspaces, the beanbag chair, and the classroom) and domains (such as computer science, engineering, and the physical sciences). More information about current projects can be found at www.snowdaylearninglab.org.