Sketching is considered a helpful activity in STEM design and education. Scholars have argued for including children in designing technology as it has been found to improve product design and leads to social and cognitive benefits for children. However, little is known about children’s learning and sketching experiences when participating in design activities. How do children sketch during design activities? How do children learn about sketching in design activities? What information do they share via their sketches? What information do they use for sketching? How do they use sketching in the overall design process? How do learning and sketching relate to STEM design? This three-paper dissertation uses empirical and theoretical approaches to address these questions. The first paper uses an ethnographic case study approach to qualitatively examine information-sharing practices and learning opportunities from children’s engagement in interest-driven sketching. Findings suggest that sketching can provide multiple learning opportunities to children. Also, it can be helpful to gather information about the broader contexts of children’s lives which can help identify their needs and improve the future design of technologies for children. The second paper presents a theoretical framework, Radical Constructivist Cooperative Inquiry (RCCI), for understanding children’s learning in design activities. Based on the theoretical synthesis of the cooperative inquiry design approach and the radical constructivist perspective of learning, RCCI establishes six pillars of learning in design. Finally, the paper discusses how these six pillars can be utilized in design activities to support children’s learning. The third paper is a secondary analysis of video data of children’s learning and sketching experiences in engineering design in their home environments. It focuses on examining the relationship between children’s sketching and learning following the RCCI framework with the thematic analysis method. Results suggest that sketching can engage children in learning about STEM skill sets. These three papers collectively contribute empirically and theoretically to building knowledge about improving and sustaining design cycles by children in STEM learning contexts.