Investigating the Status of Main Components of Environmental Lessons in the Textbooks of the Tenth Grade Schools in Iran

The purpose of this study was to investigate the position of environmental components in the tenth grade textbooks in Iran. The research method was descriptive using content analysis. The statistical population included the books of the tenth Grade Schools, investigated totally without any sampling. A researcher-made content analysis inventory which was compiled by expert judgments and examined by descriptive indices using analytical process of Shannon Entropy, was employed to gather data. The result showed that:1. The frequency of environmental components in the tenth grade textbooks of humanities was 410, in natural sciences was 679 and in mathematics - physics was 535. 2- In the tenth grade textbooks of the humanities, component " Sanitation and Health" with importance coefficient of 0.181 was the most important dimension and component " population" with importance coefficient of 0.067 was the least important dimension. 3. In the tenth grade textbooks of the natural science, component " wildlife " with importance coefficient of 0.125 was the most important dimension and component "population" with importance coefficient of 0.008 was the least important dimension. 3. In the tenth grade textbooks of the mathematics, component "sustainable consumption" with importance coefficient of 0.141 was the most important dimension and components “problems of and threats to the environment”, and "population" with importance coefficient of 0.03 and 0.01, respectively were the least important dimensions.