So, what you do is you set up a couple of displays, one where the block is stopped, the other one where you take this away with a trap door and it keeps going.

所以,你可以设计几个演示,一个是木块被挡住了,另一个是用活门把木块挪开,使得屏板继续上升

耶鲁公开课 - 心理学导论课程节选

But if we could statistically control for every other variable, all I'd need to do is measure the distance from your door to everybody else's door on campus and I could chart out who's going to fall in love with whom on the Yale campus.

如果我们能精确地控制其他可变因素，那么只需要测测距离,你宿舍门到其他宿舍门的距离,我就能够计算出,校园里谁爱上了谁。

耶鲁公开课 - 心理学导论课程节选