Spaced vs massed practice has an effect size of .59, which means that if it’s done right and often, students have the potential to accelerate learning (.40 is average growth) in the space of one academic year. 

The method also has other benefits, including:

• Enhancing learning and long-term information retention

• Working no matter what phase of learning a student is in, or the learning intention that the teacher has for the student(s)

• Using it with other strategies like interleaving (mixing old and new material in with current) and retrieval practice (a.k.a. practice testing)

As you watch the videos below, ask yourself, "How do these ideas fit together?"