"Houston,while you're looking that up, you might recognize what I have in my hand as the handle for the contingency sample return;

VOA: special.2011.05.15

We can define it in a couple of different ways depending on whether we're talking about sample mean or population mean.

我们有几种不同的方式去定义这个概念,取决于我们指的是,样本均值还是总体均值

耶鲁公开课 - 金融市场课程节选

And the other thing you can do is take self reports like the ones you're doing, hopefully do enough of them, and a random enough sample of the population, that you can extrapolate from that sample to the whole population, and try to estimate what people are eating in that way.

还有其他可以做的,比如大家正在做的这种个体调查,希望能把它做的充分些,如果有充足的随机样本,就可以从样本推断出,整个总体,从而推断哪类人有这样的饮食习惯

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

And you know, even if people are doing these things anonymously, or they're part of a big national sample where they're one of thousands and thousands of subjects, people don't necessarily like to say that they're doing something that they don't think they should be doing.

你知道,即使人们参加的是匿名调查,或他们是全国性样本中的一员,他们是那数以千计万计总体中的一员,人们似乎也没有必要说出,他们做的一些,自认为不应该做的事情

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选