Mindframes Flashcards - Based on the Leitner System

The Leitner System

The "Leitner system" is a method of effectively reviewing flashcards to quickly achieve long-lasting memorization.

To illustrate how it works, suppose you start with five flashcard stacks numbered 1 through 5, with all cards initially placed in Stack 3. During your review, you move correctly answered cards one stack to the right, and incorrectly answered cards all the way to the left into Stack 1.

After having worked through Stack 3, you go on to review Stack 1 (again moving correctly answered cards one stack to the right, and incorrectly answered cards back to Stack 1). You repeat the review of Stack 1 until Stack 1 is empty.

Next, you review the cards in Stack 2 (again moving correctly answered cards to the right and incorrectly answered cards back to Stack 1). After finishing Stack 2, you may decide to again review Stack 1, or alternatively do a "refresher" review of Stack 3 or Stack 4, using the same method.

You continue your study using this method for as long as you like. Throughout the process, you make sure to review the lower-numbered stacks on the left more frequently than the higher-numbered stacks on the right.

Proficiency Levels

Since incorrectly answered cards are moved to the left and correctly answered cards to the right, using this method continually sorts your flashcards into five "proficiency levels" represented by the five stacks.

Stack 1 will always contain the "least-memorized" cards and Stack 5 will contain the "best-memorized" cards. Stacks 2-4 will contain cards for which you have attained intermediate levels of proficiency.

At any given time, the distribution of the flashcards across the five stacks is a reflection of the strength of your memory with respect to these cards.

Why the Method Works

Flashcards that are difficult to remember require more frequent repetition than easily remembered cards. Study time is a limited resource.

To memorize a large number of cards, it is therefore crucial to spend the bulk of the time you have available for study reviewing cards that are difficult, and minimize the time spent on cards that are easy or already known.

This is where the Leitner method is helpful. It results in a dramatic increase in the frequency with which difficult cards are repeated during your review sessions, and a corresponding decrease in the repeat frequency of easy or already known cards.

Consider the following example illustrating the effect of the Leitner method, as compared to a "naive" method in which cards are not sorted by difficulty during review.

Example. Suppose you have a flashcard deck containing 100 cards, such that:

70 cards are already fully known to you and do not require further practice ("fully known" cards);

15 cards are somewhat familiar to you but difficult to remember ("somewhat difficult" cards);

10 cards are unfamiliar to you and very difficult to remember ("very difficult" cards); and

5 cards are unfamiliar to you and extremely difficult to remember ("extremely difficult" cards).

All these cards are currently intermingled randomly in the deck. You have set aside 60 minutes for flashcard study, and it takes you on average 3 minutes to review 10 cards.

To attain mastery of the flashcard deck, you must become proficient with the 30 cards that you do not yet fully know. Now compare the following two study methods that you could use to achieve this goal:

I. Naive Method. You spend the first 30 minutes reviewing all 100 cards in the deck, but make no attempt to separate the 30 cards that you find difficult from the 70 card that you already fully know. In the remaining 30 minutes, you again review all 100 cards.

II. Leitner Method. You proceed as follows:

Spend the first 30 minutes reviewing all 100 cards, and separating the 30 difficult cards from the 70 fully known cards by sorting them into two separate stacks;

Spend the next 9 minutes reviewing only the 30 difficult cards, and separating (i) the 15 somewhat difficult cards from (ii) the 15 very difficult and extremely difficult cards by sorting them into two separate stacks;

Spend the next 4.5 minutes reviewing only the 15 very difficult and extremely difficult cards, and separating the 5 extremely difficult cards from the 10 very difficult cards by sorting them into two separate stacks;

Spend the next 1.5 minutes reviewing the 5 extremely difficult cards;

Spend the next 1.5 minutes minutes once again reviewing the 5 extremely difficult cards;

Spend the next 4.5 minutes once again reviewing the 15 very difficult and extremely difficult cards;

Spend the next 9 minutes once again reviewing the 30 difficult cards.

Now consider the effect that each of these methods has on the use of your study time and the frequency with which the cards are repeated:

I-a. Effect of Using Naive Method. You will have reviewed (i) each fully known card 2 times, spending 42 minutes on fully known cards (36 seconds per card); (ii) each somewhat difficult card 2 times, spending 9 minutes on somewhat difficult cards (36 seconds per card); (iii) each very difficult card 2 times, spending 6 minutes on very difficult cards (36 seconds per card); and (iv) each extremely difficult card 2 times, spending 3 minutes on extremely difficult cards (36 seconds per card).

II-a. Effect of Using Leitner Method. You will have reviewed (i) each fully known card 1 time, spending 21 minutes on fully known cards (18 seconds per card); (ii) each somewhat difficult card 3 times, spending 13.5 minutes on somewhat difficult cards (54 seconds per card); (iii) each very difficult card 5 times, spending 15 minutes on very difficult cards (90 seconds per card); and (iv) each extremely difficult card 7 times, spending 10.5 minutes on extremely difficult cards (126 seconds per card).

Here are the same results as a table:

**Comparison of Naive Method vs. Leitner Method**
Difficulty Level	Number of Times Each Card in the Difficulty Level Is Reviewed		Time Spent on All Cards in the Difficulty Level		Time Spent Per Card in the Difficulty Level
	Naive Method	Leitner Method	Naive Method	Leitner Method	Naive Method	Leitner Method
Fully Known	2 times	1 time	42 minutes	21 minutes	36 seconds	18 seconds
Somewhat Difficult	2 times	3 times	9 minutes	13.5 minutes	36 seconds	54 seconds
Very Difficult	2 times	5 times	6 minutes	15 minutes	36 seconds	90 seconds
Extremely Difficult	2 times	7 times	3 minutes	10.5 minutes	36 seconds	126 seconds

The advantages of the Leitner method are clear.

If you use the naive method, you will have spent 42 minutes of your 60-minute study session on cards you already know, only 18 minutes on difficult cards, and only 3 minutes on the cards that are most difficult for you. You will have reviewed each of the most difficult cards only 2 times, and will have spent only 36 seconds on each of the most difficult cards.

By contrast, if you use the Leitner method, you will have spent only 21 minutes an already-known cards, 39 minutes on difficult cards, and 10.5 minutes on the most difficult cards. You will have reviewed each of the most difficult cards 7 times, and will have spent 126 seconds on each of the most difficult cards.

In summary, the Leitner method ensures that easy cards will get gradually excluded from review sessions, and difficult cards will be presented with ever-increasing frequency. As a result, this method can powerfully enhance your ability to quickly memorize large amounts of information.