It was only when we started to study those that we actually understood how we can best help that population.

只有当我们开始研究这些,才能了解如何帮助到整体。

哈佛公开课 - 幸福课课程节选

But you can imagine the inability to do that in a big population study with thousands and thousands of subjects, so we have to rely on data like this.

但你们可以想象在一个大样本研究中,不可能对数以千计的研究对象做这种培训,所以我们需要依靠像这样的数据

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

It's a more powerful method than something called a cross-sectional study, and I'll come back in a later lecture and talk about these in more detail, but a cross-sectional study means you're taking a snapshot of a population of people at one time.

这种方法比所谓的横断面研究更加有效,我将在以后的课中,再仔细讨论这个问题,但横断面研究是指,你一次记录下一群人的状况

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

Well, a cross-sectional study would mean that you'd get a random group of the population and measure them in 1970 and then take another random group five years later and measure them, but it wouldn't be the same people necessarily, it would be different groups of people.

那么,横断面研究就是,1970年你在人群中随意选择一组人,并记录下相关数据,然后,五年后再随意选择一组人记录数据,但这不需要是同一组人,通常是不同的人

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选