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Document Version: 1.2
Last Modified: 2010.05.10

Flashcard study is useful to many kinds of learners and they have different kinds of needs depending on the content of their study. An evaluation of a given piece of software will depend completely on whether it meets the needs of the learner in question. The reviews on this site of flashcard software available for Mac OS X are aimed for language learners and primarily those who want to use these applications for vocabulary review.

Flashcard developers need to focus on these basics:

Fast and easy entry – don’t make us work when we have to enter dozens or hundreds of entries. We should be able to do it by keyboard alone and the keyboard input method should be remembered.

Easy editing and organization of entries – Make it easy for us to organize, within a single file, multiple sets or categories of words and to quickly and easily edit our entries in list view and also while we study.

Graded slideshow study method – A must for studying large numbers of words. See below.

Study on demand – Allow students to study the words they want to study when they want to study them when we are preparing for those quizzes and tests.

Interval study – Long term memory management means spaced repetition. This separates the boys from the men in the flashcard software world. See below.

Cycle elimination – During flashcard study students must be able to cycle through words, reviewing incorrect ones until we get them all right.

Data Portability – Users want to have full control over their data. You should make it easy for them to get data in, but also give them the freedom to move their data out again when you no longer meet their needs and they wish to move on to a better environment.

Below is more detail on what the best flashcard applications for students of language have to offer:


A flashcard application must allow the input of cards with at least 2 but optionally more than 2 fields of information. 2 fields may be enough if you are learning Swedish and don’t want to worry about verb conjugations, but if you are studying languages like Chinese and Japanese most learners will want to have a field for the Chinese character, the pronunciation, and the English meaning. For other languages, keeping various conjugations of verbs in separate fields for practice independently is one desirable feature to offer.


The flashcard application must work smoothly with all languages, including non-Roman languages such as those of East Asia and right-to-left languages such as Hebrew.

Ease of Input

A flashcard application must allow simple and fast input of words. Some students will be inputting dozens of new words every day if they are in an intensive language study program and won’t want to do a lot of clicking about. It should be easy to move between the fields one is editing by keyboard motions and also easy to move, by keyboard alone, to the creation of a new word. Ideally, the Input Source should remain consistent when new words are created. I should not have to switch to the Russian keyboard every time I create a new word – it should remember that I was typing Russian in the field in question the last time I typed a word.

Ease of Organization

A good flashcard application provides a way to organize a group of cards into a set (or stack, deck, case, etc.). Ideally it should be possible to easily organize multiple sets within a single flashcard file. For example, I may have hundreds of sets inside my “Japanese” flashcard file, and hundreds more in my “Chinese” flashcard file.  This prevents the need to constantly open separate files for sets.  An iTunes style sidebar for organizing sets is one easy way to manage this system.  It should be possible to put the same cards in multiple sets.

Modes of Study

There are three modes of study that are commonly found in flashcard software: fill-in-the-blank, multiple choice, and graded slideshows. Of these, by far the most important is the graded slideshow. The graded slideshow is the exact digital equivalent of studying with paper flashcards. Any good flashcard application should focus its energies on creating the best possible graded slideshow mode. In many languages, having the option of fill-in-the-blank is also useful, especially at the early stages of learning for new vocabulary. Multiple choice is close to useless.

  1. Multiple Choice: Multiple choice tests are a way for test writers to create an easily gradable question for a test. It helps the grader. Pedagogically, compared to other modes of study, it provides very little help to the student. Learning to distinguish answers from other answers in a limited set of vocabulary words is not the same as memorizing a word. In a vocabulary training program, therefore, multiple choice is often included because a) it is easy for programmers to develop and b) learners can move through these multiple choice cards fast while having the deceptive satisfaction that they are being objectively evaluated.  Multiple choice study modes fools both the programmer and the user of the software into thinking they have accomplished something. 
  2. Fill-in-the-blank: Fill in the blank study mode forces the student to type in the translation for a given vocabulary word. This is useful for learning words in a language where learning the word requires mastering exact spelling, accent placement, or correct tone marks. However, it is usually most useful in the very early stage of learning a word. There are two major problems with this mode of study:1) It is difficult to effectively implement in software with enough flexibility to accommodate slight differences in answers produced by students. If the translation of a word is a full phrase, the student might have the correct answer but type it slightly different. Different software programs deal with this in different ways, but it often involves the student inputting multiple possible accepted answers.2) The biggest problem with this mode of study comes in the long term and is a problem that many flashcard software developers fail to realize. When a language learner is learning hundreds of words in a language, they must also review dozens, sometimes over a hundred words every day. Because a single review session with, say, fifty words might involve cycling through many of these words two or three times, doing a fill-in-the-blank flashcard review session might involve typing in over a hundred words. This has a huge cost for the learner in terms of time (it takes time to type in the answers) and physical exhaustion (typing lots of words tires the hands). For this reason, if this mode of study is available, I recommend only using it with new words. 
  3. Graded Slideshow: This is the mode of study which is the equivalent of studying with paper flashcards. When a student sits down to memorize a set of words for a vocabulary quiz they write down the words on one side of the card and the translation on the other. They then “flash” through these cards. They keep “flashing” through the cards until they start finding that they know some of the words by heart. When they have memorized a word, they usually will put that card to the side, thus reducing the total number of cards in the pile. They continue to remove cards they are confident they know well and only continue flashing through those they have not memorized. When they have removed all the cards to the “known” pile they can be said to have memorized that pile of cards. Depending on the needs of the learner, they may then reverse the direction of study, going through the same cards but starting by showing the opposite side. Memorizing cards in one direction is a sure way to achieving only passive, not active mastery of vocabulary.  When this is implemented in software, there is some method by which the student “flips” the card digitally speaking to show the content on the “back” (or in the case of cards with more than 2 fields, show one or more of the remaining available fields). It must be graded, that is to say, the software must have some way to mark words as “memorized” and then leave that card out of the next cycle of that review session, continuing this until the student has memorized all the words.The disadvantage of the graded slideshow and its paper equivalent flashcard study is simply that it depends on the honesty of the learner to identify which cards they have really memorized or not. However, by marking words “learnt” or “memorized” that you actually got wrong you are only doing yourself a disservice. Sometimes, however, a learner will conclude that they were “close enough” and mark a word learnt. This is all up to the learner. Flashcard software is for learning, not for testing. Therefor this disadvantage is not a major problem.The advantages of this mode of study are huge: if done right, graded slideshows are easy to program and, just like their paper equivalent, an incredibly fast and convenient way for learners to memorize a set of words. When the student reaches the stage where they are reviewing hundreds or thousands of words previously learned, the graded slideshow is the only viable option for fast and effective daily review.

Interval Study

There is no longer any excuse for serious flashcard developers. Interval study, spaced repetition, the Leitner method; whatever you call it, the benefits of studying content at increasingly spaced intervals are well documented. Any good flashcard software application should work hard to implement interval study. When interval study is activated or turned on, every time a word is studied its “stage” in the learning process increments. The more times you correctly review a word, the longer you can remember it. Thus, an interval study system will track the statistics of every word you study and the higher its interval study number is, the longer the time will pass before the software will prompt you to review that word. It is important that the interval increases with the number of times a word is reviewed correctly but ideally the interval should drop or even reset if the learner gets a word wrong.

With a good interval study system, the learner should be able to open the software up every day, press a single button and be presented with the words they are “on the verge of forgetting.”

A good implementation of interval study should allow certain flexibility in this system:

  1. It should allow students to tweak the “time-to-forget” (TTF) schedule for their own needs. Not everyone has as good a memory as everyone else. They should be able to adjust the size of the interval (number of days) between reviews of a word at any given stage. Some people may not need to review a word for three days after the second time they get it correct, but others may need to review it again the following day or after two days. The TTF schedule should be customizable.
  2. If the learner has gone on vacation for two weeks, they may return to find that interval study prompts them to review several hundred words. The software should allow the user to randomly (or determine by some other filter) review a limited number of entries from among those that the learner is on the verge of forgetting.
  3. Interval study statistics should only be saved the first “cycle” through the flashcards. They should then be able to continue practicing the words until they have memorized them all.
  4. Ideally, the software should allow the user to determine what happens to words marked incorrect on the first cycle. Dropping the interval stage by 1 or 2, or resetting the word completely might be options.
  5. Ideally, the software should provide some way for students to easily modify the interval stage of single or multiple cards.


Media such as images and sound are a nice bonus but usually only professional quality sets produced by a language instructor or other institution will have the time to add sounds or images for cards. Images provide memory triggers that can speed memorization but are time-consuming to add and space-consuming to save. When language learners are adding dozens of words every day or week on their own, they often do not have time to add such niceties. Adding sounds for pronunciation can also be useful, but is usually best for complete beginners who have not mastered the sounds of a new language. They will often need a native speaker to record the sounds at any rate.

Thus, while developers often spend huge efforts to create nice drag-and-drop or import systems for sound and images and agonize over how to display and incorporate these sounds and images into flashcard study, they may be taking important development time away from the more important features above. Don’t be fooled by applications with great sound and image features – unless you are a medical student studying anatomy etc., this is not what the majority of language learners need in their flashcard software.


Once a learner progresses in his or her study, having quick and easy access to statistics about one’s study can be very useful. Here are some types of reference data about vocabulary that has been studied that might be useful to a user:

  1. When the card is next scheduled for study (=today+interval length for this stage). A chart showing how many words are scheduled for individual upcoming days can also help students predict how much time they will have to allocate for study in the days ahead and monitor or regulate the amount of new words they attempt to learn.
  2. When the card was last studied.
  3. What interval stage a given word is at (students should be able to modify this).
  4. How many times a card has been marked wrong in its “career.”
  5. How many times a card has been marked correct in its “career.” (this may not correspond to the interval stage, since cards may move back and forth as it is remembered and forgotten later)
  6. How many cycles in the last study session (or on average) it took for a word to finally get memorized. This can help a student determine the “stickiness” or difficulty of a word. More difficult words must be viewed several times in any given study session before it finally “sticks” in memory.
  7. What percentage of cards from the first cycle of a study session were marked correct, perhaps with a chart showing this across multiple study sessions to show average performance across time.
  8. The total and/or average number of cards marked wrong at each interval stage. This can help a student determine what stage is their “magic spot,” for most words, after which a card really begins to enter into long-term memory.  For me it is stage 4: if I get a word correct four times on three separate study sessions, then the word is usually “home-free” and I can go very long periods of time without reviewing it.

Data Portability

Flashcard applications should make it easy to import information into your software or website but smart users will avoid allowing themselves become trapped into using one resource. Who wants to invest many hours inputting or searching for flashcards if they are trapped and forced to use your resource forever? They want to be able to easily export their flashcards and move on to the next resource should your project ever die or fail to keep up with the pace of development. Many developers use a strong database of flashcards or good features to lure in users and then trap them by making it difficult or impossible to get their data out in the form of a tab or comma delimited text file that they can easily move to another application.

Unfortunately, there is no standard algorithm or format for interval study (SRS) statistics, so rarely does this data travel well from one application to another. However, ideally, all SRS/interval study supporting applications should optionally allow students to export this data as well, in case other applications are able to interpret and import this information in some meaningful way.