Basically, it discusses how our working memory preferentially keeps things around that are “unfinished” like waiters keeping orders in mind only until they are finished.

But they also did an experiment asking people to solve difficult puzzles, then interrupted them and told them the study was over. About 90% of people kept working on the puzzle anyway. As the article says, this Zeignarnik Effect could also be called the “Cliffhanger Effect” because it keeps you interested the same way a TV episode with a cliffhanger ending keeps you wanting to watch the show again.

Anyway, from this I can derive there are two benefits from this method of studying. The first is that it improves your memory since you are “interrupted” (by the timer) before completing the task. If my task is to study a chapter of Mandarin, but I only get through half of the material, it is an “unfinished task” (like a waiter’s order that hasn’t been filled) and gets preferential treatment. The second is that it improves motivation like a cliffhanger ending.