Writing challenge. Day 2. Today I am going to continue my theme about the spaced repetition technique. I decided to make my entries not bigger than 350 words because it shouldn't take too much time to correct. Well, the notion of spaced repetition was firstly proposed by Prof. C. A. Mace in 1932 in the book "Psychology of Study". He wrote that learned material should be revisioned in gradually increasing intervals. Because this approach gives a possibility to remember learning material more deeply. Later this idea went to the manual style of learning with physical flashcards that was proposed by Sebastian Leitner. Generally, the idea of flashcards in vocabulary learning context works as follows: - Whenever a student comes across a new word he creates a card. One side of this card contains the new word and the back side contains the translation. - A student sorts cards by three groups. The first group includes cards with new words. The second group is a transitional place. The third group is for cards that student knows very well. - A student studies cards from the first group - each day, cards from the second group - every three days and cards from the third group - every 5 days. - Each time when a student gives the right answer looking at a question on the card, the card goes from the current group to the group with a bigger number. - If a student doesn't remember the answer or makes the wrong one, the card goes to the previous group. Even this simple method might significantly improve your vocabulary studying process. But it's good for the old times and later I will tell you how to change manual flashcards to the contemporary way of studying with a similar technique.