Stahly, Krockover & Shepardson (1999) looked into third graders’ ideas about the Moon’s
phases both before and after instruction. Their methods used interviews from four students from
a third grade class of 21. These students varied in abilities and were chosen based on criteria
that included their communication skills. The instruction the students received consisted of 6
lessons over a period of 3 weeks, which included the presentation of a 3D model of the
Sun/Earth/Moon system. With the researcher acting as a teacher, the material was presented to
the students to facilitate their learning while their concepts and conceptual changes were
monitored and recorded. Results were obtained from interviews and drawings made by the
students.