And so, there is the distinction between fixed schedules versus ratios, variable schedules and ratio versus interval.

因此，在固定时程与变化时程之间,以及在比率与间隔之间，存在着一些区别。

耶鲁公开课 - 心理学导论课程节选

Real life for both humans and animals involved cases where the reinforcement doesn't happen all the time but actually happens according to different schedules.

在现实中，人类和动物,并不总是不停的得到强化,但实际上强化则是根据不同的时程出现的。

耶鲁公开课 - 心理学导论课程节选

And fixed versus variable speaks to whether you give a reward on a fixed schedule, every fifth time, or variable, sometimes on the third time, sometimes on the seventh time, and so on.

固定与变化则是相对于,你是否根据固定时程给予奖励而言的，每五次就给予奖励，或者是变化的，有时候在第三次上给予奖励，有时候则在第七次上给予奖励。

耶鲁公开课 - 心理学导论课程节选