As discussed in the chapter on the spacing effect, it is generally better to space the study of a particular item of information over multiple sessions rather than repeatedly study the item in a single session. Spacing learning out increases long-term retention. One thing to note is that learners are often unaware that spacing out study leads to better learning [3]. An ideal study strategy is to create large decks of flashcards and then study those decks in the weeks leading up to any test or exam. This naturally spaces out the items. Depending on the number of items to learn, a relatively short practice session each day may be sufficient.

Nate Kornell and Robert Bjork carried out four experiments regarding the dropping of flashcards from a deck. Students who dropped the flashcards did worse than those who continued to study all the flashcards. Participants typically dropped items they thought they knew, however, this strategy failed to deliver improved performance in a final exam. Often students mistakenly believed that one successful retrieval proved they knew the item, not realising that even items that seem committed to long term memory can be easily forgotten. The study demonstrates the benefits of continued review and testing of items that have already been successfully retrieved [4].

Nate Kornell also conducted a series of experiments regarding flashcard strategy. In the first experiment, he compared studying four smaller decks of flashcards versus one large deck of flashcards. Each flashcard was studied four times. He found that students who studied the larger deck did better on a final test. This result illustrates the importance of spacing out items when studying. A second experiment confirmed the general finding that massing together items to be studied resulted in worse performance than spacing them out, even when the total number of times a card was studied remained the same. A third experiment, which incorporated a final review session before the final exam, continued to show the benefits of spacing out cards to be studied. In general, students should use relatively large decks of flashcards and space their study over multiple days. One thing to note is that it is often perceived that massed study (repeatedly studying the same item with little gap between repetitions) was more efficient despite the opposite being true [3].

A number of strategies are possible, but a simple and effective approach is to use one deck per class. This enables interleaving of different topics as well as adequate space between successive presentations of an item. Also think about how you can use flashcards to process information at a deeper level, rather than just repetition. Incorporate different kinds of information on the flashcard. For example, the front of the flashcard could be the keyword, and the back might include the definition as well as a couple of examples if applicable.

There are many sources of flashcards. For instance, some textbooks have flashcards available on the corresponding website. Similarly, some publishers produce books of flashcards for popular topics. In addition, students may share decks of cards they have created. You may be wondering whether it better to use these existing resources or to create your own? It’s commonly theorised that making your own is better due to the learning processes that occur during card creation [5], yet studies that compare the two approaches have shown mixed results with no definitive advantage for user-generated cards.

A study by Pan and associates examined whether given a fixed amount of time if it is better to create your own digital flashcards or to use those created by someone else. In a series of experiments, participants had 20-25 minutes to make and review flashcards or to just review provided flashcards for a text passage. Two days later they took a test. The researchers found hat user generated flashcards enhanced learning compared to premade [5].

In contrast, Wilkinson examined the effectiveness of flashcards for learning foreign language vocabulary. In one experiment, he compared participants who made their own flashcards (and studied from them) versus those who spent the same amount of time studying from premade cards. In the short term, those who used the premade cards performed better. However, after 8 weeks there was no difference between the two groups [6].

Research by Cihon and colleagues found in a study of undergraduate students that those who received instructor-provided flashcards performed better than those who made their own flashcards. They hypothesised that this may have been due to the undergraduates being unable to identify the most important information. In a similar experiment with graduate students they failed to find a difference between the two conditions [7].

It’s worth pointing out that many flashcard experiments don’t closely reflect real world conditions, so any conclusions are only tentative. It’s also unlikely the debate over user-generated vs premade flashcards will be definitively resolved given the number of variables interacting.

It can take a long time to make quality flashcards (paper or digital). Students typically only have a fixed study time, with premade cards that entire time can be devoted to revising the cards. Whereas with user-generated cards, that time must be divided between constructing cards and revising. Given the current evidence, a reasonable approach is to make your own cards if you have time and prefer, but there is no point being dogmatic about it. Another important factor is the quality of the flashcards. If the only premade cards available are of poor quality, it is better to make your own or to take an existing deck and revise it. For those who are struggling with a course, see if you can get a deck from someone who got an A grade in the previous year.

Some people at your university might refuse to share their decks of digital flashcards and justify it by saying it is better to make your own. However, based on the evidence to date, it’s impossible to reach such a conclusion. It’s more likely they don’t want to give you an advantage in a competitive course or don’t like others benefiting from their hard work.

Flashcards are especially popular among those who are taking foreign language courses. In language learning research, the first language is referred to as L1 and the second language that is being acquired is referred to as L2. Flashcards for language learning cards can be organised in many ways. For example, a Spanish learner could be presented with a picture of a shoe and have to respond with "el zapato", or they could be presented with the english word green and have to respond "verde". With the move to flashcard software, audio clips can also be incorporated.

We can distinguish between productive and receptive retrieval. Productive is when the prompt is the meaning and the student has to remember the corresponding L2 word. Receptive is when the student is prompted with the L2 word and has to remember the meaning. So for a student studying Japanese if the prompt is "delicious", and they have to remember "oishii" that is productive retrieval. In contrast, if they are given "oishii" and have to remember that it means delicious, then that is receptive retrieval. Research suggests that if learners want to be successful at both productive and receptive retrieval, they should practice both. Nevertheless, productive retrieval has been shown to produce sizeable increases in receptive knowledge, whereas the converse isn’t true. So if learners are pressed for time, their flash cards should favour productive retrieval [8].

When it comes to vocabulary learning it is recommended to favour larger gaps between retrievals (testing) because although this leads to more failures during learning, it leads to superior retention longer term [8]. Most students who are studying languages are doing so with the intention of becoming fluent rather than just getting high marks in a particular university assessment.

Digital flashcards have a number of advantages such as:

A study by Robert Ashcroft and associates compared digital and paper flashcards for Japanese university students learning English. The students who were worse at English did better with digital flashcards, whereas the students who were more proficient at English did equally well with the digital and paper flashcards [9].

Flashcard software often implements some fairly complicated algorithms to decide when to present a card to the learner. Yet comprehensive research that supports the benefits of these algorithms is lacking.

Spacing schedules can be categorised as expanding, equal spacing, or contracting. Expanding spacing refers to a practice schedule where the gaps between presentations of a given item are increased in an expanding manner such as one week, two weeks, four weeks, etc. In equal spacing the item might be presented every two weeks. Contracting is more uncommon, but works like you would expect. The gap between presentations could start at eight weeks, then four weeks and so on.

It is unlikely that there is one algorithm or schedule that is substantially better than another. A study by Jeffrey Karpicke and Althea Bauernschmidt found no evidence that expanding, equal, or contracting intervals was superior to any of the others [10].

Previously, we discussed both the testing and the spacing effect and how they have been shown to boost learning. The testing effect refers to the phenomenon that learning is enhanced when material is tested rather than simply restudied. The spacing effect refers to the learning advantage when the items to be studied are spaced out as opposed to being massed together. Flashcards naturally incorporate both effects.

Digital flashcards offer many advantages over paper flashcards, but it is fine to use paper cards if preferred. It is recommended to use premade decks if available due to the fact that creating your own cards takes a lot of time and there isn’t evidence for any major benefit.

An optimal way of organising cards is to have one deck of cards per course rather than one deck per topic. This facilitates spacing out of the cards. A common practice is to drop cards from the deck once the learner got the answer correct, but research suggests it is better to keep studying the card.

[1] J. M. Golding, N. E. Wasarhaley, and B. Fletcher, “The use of flashcards in an introduction to psychology class,” Teaching of Psychology, vol. 39, no. 3, pp. 199–202, 2012.

[2] I. Zung, M. N. Imundo, and S. C. Pan, “How do college students use digital flashcards during self-regulated learning?,” Memory, vol. 30, no. 8, pp. 923–941, 2022.

[3] N. Kornell, “Optimising learning using flashcards: Spacing is more effective than cramming,” Applied Cognitive Psychology: The Official Journal of the Society for Applied Research in Memory and Cognition, vol. 23, no. 9, pp. 1297–1317, 2009.

[4] N. Kornell and R. A. Bjork, “Optimising self-regulated study: The benefits—and costs—of dropping flashcards,” Memory, vol. 16, no. 2, pp. 125–136, 2008.

[5] S. C. Pan, I. Zung, M. N. Imundo, X. Zhang, and Y. Qiu, “User-generated digital flashcards yield better learning than premade flashcards.,” Journal of Applied Research in Memory and Cognition, vol. 12, no. 4, p. 574, 2023.

[6] D. Wilkinson, “Deliberate vocabulary learning from word cards,” Vocabulary Learning and Instruction, vol. 9, no. 2, pp. 69–74, 2020.

[7] T. M. Cihon, A. M. Sturtz, and J. Eshleman, “The effects of instructor-provided or student-created flashcards with weekly, one-minute timings on unit quiz scores in introduction to applied behavior analysis courses,” European Journal of Behavior Analysis, vol. 13, no. 1, pp. 47–57, 2012.

[8] T. Nakata, “Learning words with flash cards and word cards,” The Routledge handbook of vocabulary studies, pp. 304–319, 2019.

[9] R. J. Ashcroft, R. Cvitkovic, and M. Praver, “Digital flashcard L2 Vocabulary learning out-performs traditional flashcards at lower proficiency levels: A mixed-methods study of 139 Japanese university students,” The EuroCALL Review, vol. 26, no. 1, pp. 14–28, 2018.

[10] J. D. Karpicke and A. Bauernschmidt, “Spaced retrieval: absolute spacing enhances learning regardless of relative spacing.,” Journal of Experimental Psychology: Learning, Memory, and Cognition, vol. 37, no. 5, p. 1250, 2011.