Although massed practice may be useful for understanding material within a limited duration (short term memory), retention is not as effective using this method compared to distributive learning. This is why cramming material before a test is not the most effective way to actually retain the information learned from that short studying period, whereas distributive practice allows for breaks between practice to strengthen retention and retrieval (practice makes perfect!) We should think of studying strategies that discourage cramming in learning.

If you continue to practice/review material over an extended period of time even after a test, you will retain more information as well as relearn the material quicker after some time. (More time spent on subject = more mastery)

This is quite similar to the concept of schemas.

This might be off topic, but this reminds me of how studies have shown that students who chew gum or listen to a specific playlist while studying tend to perform better on exams when they chew the same gum or listen to the same music during the test as well. Just an interesting thought that might correlate to the study.

We should try to obtain observable data and methods that will allow us to specifically measure the process of learning and its effectiveness, instead of just looking at the results from tests and exams.