This is based on two realities: one, we don't retain very much unless it is periodically reinforced, and two, many of our learners are more interested in "passing" than learning and will breeze through material as quickly as they can if we let them.
Most current eLearning nevertheless seems to find this principle too arduous, and has replaced frequent check-ins with the use of simple interactivity to keep the learner engaged, even if all that happens in these interactions is to reveal more content.
The trend is even more apparent with the conversion of university courses to online lectures.
Knowledge checks, if they are present at all, are reserved for the ends of modules or sections.
And when was the last time you had to repeat material in an online course because you were judged to have not understood it? Probably never.
I'm not saying the 3-idea principle is always practical. Frequent reinforcement makes for great eLearning. but It is possible to overdo it.
We should, however, keep this worthy goal in mind and make sure we aren't just creating courses just to fulfill someone's mandate rather than communicating knowledge.
P.S., Have your own stories about embedded questions or topics for new cartoons?
Please leave them in the comments!