Forward testing effect: Taking an exam before learning the subject can enhance future learning of that subject.
Book: Ultralearning
The forward testing effect is a phenomenon observed in memory retrieval research where testing one's memory of information that has not yet been learned can enhance future learning of related information. In other words, taking an exam before learning the subject can improve future learning of that subject.
Several mechanisms have been proposed to explain the forward testing effect. Some researchers suggest that attempting to find answers to questions that have yet to be learned can strengthen one's ability to search for and identify relevant information when it is later encountered. It is like paving a road to a building that hasn't been built. The destination has yet to exist, but the road has been paved so that the resources are pre-allocated for finding the answer.
Other researchers propose that the effect may be related to attentional processes, where attempting to answer unknown questions can focus one's attention on potential relevant information. This reminds me of the days when I took the GRE reading comprehension exam, where I figured out the fastest way to complete the exam was to skim through the questions first to get a general overview of an article.