validity of quasi-experimental analysis

例句：

1. 1. Thenew policy has been shown to have ahigh validity in the experiment.
   新政策在实验中显示出很高的有效性。
2. 2. Thestudy found that the drughad a significant effect on thepatient's health.
   研究发现该药物对患者的健康有显著影响。
3. 3. The researcher tested the hypothesis with a large samplesize to ensure its validity.
   研究者用一个较大的样本量来测试这个假设，以确保其有效性。