You’ve got a big presentation, exam, or performance tomorrow, and you are feeling unprepared? Then you have little choice but to engage in some good old-fashioned cramming. Cramming is characterized by a period in which learning is neglected, followed by a period of intense study. Few people will have made it through their formal education without having engaged in this popular learning strategy. Cramming increases learning time, and there is a utility to recency for recalling information. Cramming works well if the only goal is a short-term performance boost (e.g. on an exam), but it is not suitable for long-term retention of knowledge or development of skills.
Learning scientists use the term massed practice to describe cramming and similar learning behavior. Massed practice is a learning strategy that concentrates learning into long and intense, but infrequent or even single learning sessions without sufficient breaks. Research has shown that massed practice can improve test scores in the short term, but that this strategy leads to much faster forgetting than if the learner studied the same amount of time, but distributed practice across multiple sessions. Despite the possible short-term benefits of cramming, crammers have lower overall performance over time. The increased level of forgetting probably causes problems when learners attempt to master more advanced subjects that require the knowledge they have already forgotten.
Cramming is a very popular strategy among students studying for exams. With heavy workloads and pressure to perform, it is unsurprising that students look for ways to optimize their study time. Surveys find that cramming is one of the most common learning strategies. Many learners perceive cramming as effective. The popularity of this strategy can be explained by the fluency that results from a massed practice session. After several hours of intense practice, the material will inevitably feel familiar. But this familiarity is only an illusion of competence . Cramming feels effective, but it is not.
Massed study is seductive, and it can appear to be more effective than spaced study even when spaced study is the more effective strategy
— , Applied Cognitive Psychology
Crammed material is subject to rapid decay, meaning that it is quickly forgotten. That effect is compounded if the cramming interferes with sleep. Learning occurs through the formation and consolidation of new memories into long-term storage, in which sleep plays an important role. Sleep deprivation interferes with memory consolidation, which leads to forgetting. The common practice of learning through the night — or pulling an all-nighter — was found to be an ineffective learning strategy, leading to a 40% reduction in the ability of sleep-deprived learners to retain new facts. The all-nighter may allow a learner to cram a few more facts into their memory, but the chances of retaining that knowledge long-term are damaged. Sleep deprivation is also likely to detriment performance the next day.
The main drivers behind the selection of cramming as a strategy appear to be procrastination and poor time management. To avoid procrastination, a person’s motivation to learn must exceed their aversion to the often challenging task of learning something new.
When learning for a high-stakes test or exam, there is no harm in engaging in an intense learning session the day before. But cramming should not be the only learning strategy used. Organizing learning into multiple sessions over a longer time will lead to better performance on the test and longer retention.