Methods According to the method of cluster sampling,a total sample of 3385 pupils in six grades were selected from four rural primary schools with full six grades in north areas of Zhejiang Province.

 
  • 方法采用整群抽样的方法抽取浙北地区4所农村完全小学6个年级共3385名学生,调查研究对象伤害相关知识掌握情况与安全行为习惯养成情况。
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