In the present study, the authors assessed upper secondary school students’ understanding of the gases given off and taken in by respiration and photosynthesis in regard to Priestly’s experiment. Their findings include : among upper secondary school students who considered the situation of Priestly’s experiment (1) many students listed six main essential elements for life (photosynthesis, respiration, water, food, temperature, and others), (2) many students did not refer to respiration, one of the most important elements for plants, and (3) only a few students were able to determine and understand that both O2 and CO2 gases are given off and taken in by respiration and photosynthesis. According to these results, the authors proposed a strategy that focuses on improving upper secondary school students’ understanding of respiration and photosynthesis.

This study was designed to examine the degree to which a “sociocultural approach to mediated action” is appropriate approach to understand the process of learning in science classrooms. First, we discuss the differences between the sociocultural approach and mainstream constructivism in terms of their respective theories and methods of science learning. Secondly, we outline its roots in ideas developed by L.S. Vygotsky and M.M. Bakhtin. Thirdly, to demonstrate the usefulness of Bakhtin’s ideas for understanding the process of science learning, we conducted an interaction analysis in a sixth-grade classroom. Date included videotapes, transcripts, and drawings of body arrangements. In the course of their interactions, teacher and students are ventriloquating the voices, social languages, and speech genres of their utterances each other. We conclude that the sociocultural approach to mediated action can provide a new perspective on science education in the same sense that we can discuss details of speech communication in the science classroom from this approach.

By gradually increasing the pressure inside an air gun (i.e., an air pressure tube), we measured the critical pressure necessary to fire a bullet (wad of material) from it. As a diameter of the barrel (tube), which is equal to the outer diameter of the bullet, and is proportional to the thickness of the bullet. These experimental results agree with theoretical results based on the idea that the pressure inside a barrel is equal to the friction between the barrel and the side of the bullet when the bullet is at rest. Therefore, it is hard to make a large caliber air gun that uses bullets created by pressing the barrel (tube) into some material.