Spaced Learning: Learning without "forgetting everything after the test"

Teachers and students both commonly complain about forgetfulness. "Studying for the test" and soon forgetting much of what has been studied is as frustrating as it is frequent. Some forgetting is inevitable (and even necessary), but science also shows that knowledge considered central can be maintained through effective learning strategies. Among these, "spaced practice" stands out for its effectiveness in preventing forgetfulness and prolonging learning in different levels of education and fields of knowledge. Whether as a pedagogical practice or as a method of study, a warning is needed: the implementation of this strategy challenges procrastinators...!

Spacing learning over time: "productivity" and other benefits

Generally, the spacing of learning consists in the recapitulation and re-learning of knowledge over time. Compared to the massive practice, the spaced practice produces greater retention of information for the same period of study. For example, the learning achieved in four hours of study (or instruction) tends to be less than the learning achieved in two sessions of two hours each. Moreover, spacing contributes to extend the duration of learning by allowing the consolidation of information in long-term memory, through the re-learning of contents and the course of time itself (biologically, the latter is a fundamental requirement for the creation of persistent memories). ^{(5.1, 2, 14)}

Whether as a pedagogical practice or as a method of study, research demonstrates the effectiveness of spaced practice at different levels of education, for pupils with different competence profiles, and in the various types and fields of learning, namely: declarative (such as in the study of languages and sciences), procedural (such as steps or procedures for carrying out tasks) or conditional (such as inferential learning involved in problem solving) learning. ^{(5, 6, 9, 16)}

How to implement spacing (and extend learning beyond the test)?

The spacing of learning can be applied at variable time intervals. For the initial learning phases short spacing is recommended. In order to consolidate and prolong learning, long spacing is recommended (operationalised below). ⁽¹⁰⁾

Examples of its application in the classroom:

1. At the beginning of each class, provide a brief summary of the contents of previous classes. The students' questioning is preferable to the teacher's summary. In this way, the benefits of spacing are reinforced by the practice of retrieval. The same can be done at the end of the lesson for the contents covered that day. Combining the practice of spacing with (self) monitoring of knowledge substantially enhances learning, and can also be applied between classes or during a class. For example, in extensive lessons, intermediate content recapitulation questions (from the lesson itself or from previous lessons) reinforce learning and refocus the students' attention (which tends to disperse into tasks requiring continued attention and cognitive effort).

1. Given the usual time constraints in class, recapitulations can be brief and focused on the most important contents; ^{(3, 16, 10)}
2. Recap content over a period or school year – either for the consolidation and re-learning of important knowledge or for the introduction of new knowledge (by comparing content);
3. Semi-cumulative evaluations, in which each test includes a small percentage of previous contents;
4. Homework consisting of tasks involving the revision of current and previous contents. ^{(2, 10, 14)}

Examples of implementation in autonomous study

1. In autonomous study, begin by summarising current contents, followed by the revision of previous contents; ⁽¹⁶⁾
2. Create a study schedule to space the learning in class with autonomous study (e.g., reinforce the study of a subject on days interpolated with the days of class - figure 1). This schedule favours the regulation of study and the consolidation of knowledge, and prevents intensive study on the eve of assessments; ⁽³⁾
3. Combine the practice of spacing with the practice of retrieval between study sessions, or during a study session. For example, interspacing study periods with self-evaluation of knowledge. ⁽¹⁶⁾

Spacing intervals

The estimation of the ideal spacing time between learning and relearning is a question for which research has not offered a linear response yet. In general, the longer a learning process is to be extended, the greater the spacing for relearning should be. ⁽¹⁾

Nevertheless, it is recognised that the spacing time should not exceed the information retention interval, i.e., the ability to remember some contents. Otherwise, there is significant forgetfulness, which makes it difficult to re-learn.

In general, the research suggests spacing for re-learning between 5 to 40% of the intended retention time. A rough practical example would be to recapitulate (to prolong) the learning in the following ways:

1. a spacing of one day, for one week of retention (important especially in the initial phase of learning);
2. one week spacing, for two months of retention;
3. one month spacing, for one year of retention. ⁽¹⁰⁾

Preventing intensive learning and the study of the day before

• Spaced practice, alongside recovery practice, is one of the learning strategies with the greatest empirical evidence of applicability and effectiveness in promoting sound and lasting learning. ^{(5, 6, 9, 16)}
• The application of the spacing adjusts to the routines and organisation of the class, and therefore saves additional time.
• The time necessary for the spacing and re-learning of contents considered as core is compensated by the duration of the knowledge and represents savings in terms of time in the reinstruction. ⁽²⁾
• The combination of spacing and retrieval practice substantially increases learning and can be integrated in formative exercises and assessments of knowledge consolidation as well as in formal semi-cumulative assessments.
• As a study method, spacing enhances learning and the development of self-regulatory skills, as it implies the distribution of learning over time and prevents intensive study on the day before the tests. ^{(2, 10, 14)}
• Promoting knowledge learning on a massive scale (concentrating content over time) leads to rapid forgetfulness and increases the risk of limiting learning to moments which are contingent upon formal evaluation.
• The evidence of the need for spacing and recapitulation of content to ensure the consolidation and persistence of learning has relevant implications not only for the conceptualisation of pedagogical practices but also for the objectives and organisation of teaching in general.