And there's also an experimental participation requirement, and next week I'll hand out a piece of paper describing the requirement.

我还要求你们以被试的身份去参加实验,下个星期我会给你们,一份关于要求的介绍

耶鲁公开课 - 心理学导论课程节选

These are completely optional, not required for the course, so there's no obligation for you guys to get involved in these things, but I'll mention these things as we go along in case anybody would like to get involved in working with professors or graduate students.

这些都是自愿选择的,而不是课程要求,所以并不强制你们都参加,但随着课程的进行,我还会不断提及,便于任何感兴趣的同学,能够与教授或研究生一同参与研究

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选