The Early Learning STEM Australia (ELSA) pilot was a year-long investigation involving 300 educators and 4 500 four-year old children in one hundred learning centres across Australia. This paper reports on a pedagogical and design framework that was constructed to promote children's STEM engagement across digital and non-digital learning environments. This paper describes this process in terms of a heuristic; since the educators in the study became part of the design team as they modified and adapted the activities developed by our team. The heuristic helped the educators modify and adapt the learning experiences to accommodate the diverse cultural and social needs of the students. [This paper is the second in a symposium of three papers. For the first paper, "The Role and Nature of Digital Technology Use in Preschool STEM," see ED604741. For the third paper, "The ERA Heuristic in Action: Observations from the ELSA Pilot," see ED604739.]