"Matching methods can be a powerful tool when randomization is not possible."
当随机化不可行时,匹配方法可以是一个强大的工具。
The greatest of evils and the worst of crimes is poverty.
我不介意成为一个象征,但我不想成为一个纪念碑。
不要吹开毛发去寻找小疤痕,不要洗净污垢去察看难以知晓的毛病。
创造力关乎自由,而非限制。
The only limits you have are the ones you set for yourself.