%% ### Todo - [ ] Review this [review study](https://link.springer.com/article/10.1007/s10648-012-9205-z?ck_subscriber_id=590424042) and add relevant content - [ ] https://nintil.com/massive-input-spaced-repetition/ "In some domains, and for some applications, exposure to a lot of material is superior to spaced repetition to learn that domain." - [ ] Scott Young writes: **Complexity probably favors massed practice, at least initially.** If you don’t understand something when you first encounter it, spacing will like make learning harder initially. This is probably true of all desirable difficulties, and is part of the reason most practice types involve an initial massed session where you “get” the idea, followed by spaced review. He links to [this paper](https://link.springer.com/article/10.3758/BF03196276?ck_subscriber_id=590424042). %% Spaced practice is an effective strategy for both **[[Declarative knowledge refers to factual information about the world (knowing that)|declarative]], explicit learning** as well as **unconscious, implicit learning**. The way that learners schedule their practice can have a meaningful impact on learning. Learning is usually **more rapid and/or better retained** when practice is **distributed in time rather than massed in time** – i.e., when practice is broken into separate periods of training (or "trials") that are stretched out over days or months rather than crammed in a single session. This is referred to as the **trial-spacing effect**. The study of spaced practice goes back to the late 1800s, when the German psychologist Hermann Ebbinghaus pioneered the experimental study of memory. He tried to memorize syllables over time, which led him to discover the [[The forgetting curve refers to the empirical finding that the probability of correctly recalling an item declines roughly exponentially with time unless the information is reinforced|forgetting curve]] and the spacing effect. ### Benefits - Spaced practice leads to **stronger and longer-lasting memory** than massed practice. - It appears that the main benefit of spaced practice is increased **knowledge retention**, although there are also sources that claim it may increase the speed of **knowledge acquisition**. - The benefits of spaced practice appear to be **ubiquitous**:^[National Academies, 2018; Weinstein et al., 2019] Research shows greater learning effects (i.e., better recall or performance at a later time) for spaced than for massed practice across learning materials (e.g., facts, concepts, motor skills), stimulus formats (e.g., auditory, text-based), intentional vs incidental learning, and even regardless of the size of the lag between practice and recall. The trial-spacing effect has even been demonstrated in a number of different species, including humans, rats, and even sea slugs. ### Nuances - We typically fall pray to the **illusion that massed practice is more effective** than spaced practice, because massed practice can lead to **better immediate performance** than spaced practice. Massed practice makes a visible difference within a single practice session — you make fewer mistakes, the practice feels less effortful, etc. — which is motivating and reinforces this approach to learning. However, the improvements gained during massed practice are only **temporary** and fade away quickly, because this type of practice fails to build deep and lasting capacity. - It seems that there's a **tradeoff between performance and learning** during a session of practice: If you focus on immediate performance, you get less learning, whereas if you want to learn, you need to accept worse performance in the short-term. [[There's a difference between long-term learning and short-term performance]]. - The **optimal distribution of learning sessions** depends at least partly on **how long the information needs to be retained** – i.e., when the information will be recalled in the future. For instance, if the material needs to be remembered for a test on the next day, practice intervals should be relatively short. On the other hand, if the material needs to be remembered a year later, practice intervals need to be relatively long, distributed over weeks or months. - Another factor that should be considered when distributing learning sessions is **how challenging the practice is**. If the practice feels easy, that's probably a sign to increase the intervals between sessions so that some **forgetting** occurs and the practice is effortful and engaging – see below. - [[The forgetting curve refers to the empirical finding that the probability of correctly recalling an item declines roughly exponentially with time unless the information is reinforced]]. It follows that one should distribute one's practice following an **exponential backoff algorithm**, where the delay between trials is multiplied after every successful trial. In this way, the time interval goes towards infinity, yet you never completely stop practicing. ### Application - This is fairly straightforward: Break up your practice into separate sessions and spread them out over time. - Anki is a [[Spaced repetition system]] software that manages the practice schedule based on your performance at each trial. ### Mechanism - Spaced practice underlies the brain’s ability to **[[Memory involves the stages of encoding, consolidation, and retrieval|consolidate]]** new information – to rearrange and stabilize new mental representations and store them in long-term memory, as well as integrate them with existing memories. This process can continue for hours, days, or even months, and gradually leads to simpler, better, deeper, and stronger links in long-term memory. In contrast, massed practice mainly relies on short-term memory. - It appears that the spacing of practice leads to some **forgetting** between each trial, which forces learners to **engage more deeply** in the relevant mental operations while practicing, which in turn leads to better learning. This is in line with the [[The New Theory of Disuse posits that there are two indices of memory strength – storage strength and retrieval strength|New Theory of Disuse]], which claims that deep learning (storage) occurs when the information can't be readily retrieved. - This reminds of the learning principle of [[Active engagement]], and to the [[Processing depth effect]], which suggests that deeper processing leaves a stronger mark in memory. --- Created: [[2022-09-14]] Type: #permanent Topics: [[Learning (Index)]] Related notes: - [[What are the most effective learning strategies?]] - [[Learning benefits from strategically regulated repetition and practice]] - [[Desirable difficulties refer to challenges encountered during practice that lead to stronger and more enduring learning]]