Spacing has shown to improve long-term recall more than massing by many studies. Some people however (such as E.Z. Rothkopf during in September of 1977), have posited that massing is better mode of studying when dealing with problems of induction. Kornell, N., & Bjork (2008) presented compelling evidence against this claim (spacing is also better for induction).

Effects of Spacing compared to Massing

It is the opposite of spacing: studying in long concentrated sessions rather than many short ones.

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The process of memory going from an unstable state to a more stable, permanent one. 

Memory Consolidation

Kornell, N., & Bjork, R. A. (2008). Learning concepts and categories: Is spacing the “enemy of induction”?. Psychological science, 19(6), 585-592.

Learning Concepts and Categories: Is Spacing the “Enemy of Induction”?

The major method of consolidation. The process where the hippocampus replays events associated with a memory.

Reactivation

- The standard model of consolidation
- Multiple trace model of consolidation

Memory consolidation models

- Synaptic consolidation (late-phase long-term potentiation)
- Systems consolidation
- Reconsolidation

Memory consolidation processes

Long-term recall is improved when studying is broken up into many short sessions rather than long concentrated ones (memory consolidation is improved). 

Spacing effect

Memory is most vivid and enduring when the memory takes place during a period of rapid change and is followed up with long-lasting stability (leads to better encoding/consolidation).

Cognitive hypothesis

Massing effect

Once information reaches long-term memory, it must be consolidated. This consolidation process occurs at two distinct stages: at the synaptic level, which takes a few hours, and into the broader memory system, which can take weeks or longer.

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