（上接1997年第1则）3论文中存在设计和统计问题3．1无对照组在校医或学校卫生医师的论文中经常涉及治疗效果观察或暴露在某种条件下对儿童健康的影响，在此类研究中应设立对照组，但有些论文无对照组，仅凭对实验组的观察就作出结论，这样的结论是不可靠的、不能成立的。设立 (Continued from 1997, No. 1) 3 papers exist in the design and statistical issues 3.1 no control group in the school doctor or school hygienist’s papers often involve observation or exposure to treatment effects on children’s health under certain conditions, The control group should be set up in such studies. However, in some papers, there is no control group. Only the observations made by the experimental group conclude that such conclusion is unreliable and can not be established. set up