Abstract
The purposes of this study are: 1) to investigate how third graders in elementary schools in Japan recognize the phenomenon of "parallel shadows of objects blocking direct rays of the sun"; and 2) to identify the essential knowledge and thought needed for the students to recognize the phenomenon in school science learning based on the findings of an investigation of their recognitions. The findings of this study were as follows: 1) less than 10% of the elementary school third-graders had a scientifically correct understanding of the phenomenon; 2) there were more 30 kinds of scientifically wrong answers among the third graders; and 3) nine items were identified as knowledge and thought required for recognizing the phenomenon.
