Sample sentence vs. example sentence

Hi, what is the difference between a sample sentence and an example sentence?[YSaerTTEW443543]

TOEFL listening discussions: A conversation between a research professor and a student[YSaerTTEW443543]

I think you could use either without raising eyebrows, but it would be the same as the difference between sample and example: an example is used to illustrate (exemplify) a particular point; it would more likely be constructed with that purpose, I think. A sample is just a (random) selection of a larger group (of examples, I suppose)-- anyway, it conveys a sense of being collected rather than created.

I doubt if many text writers pay any attention to the difference. Or this may be just my personal view.