As a Russian language instructor, I often hear the same question from my students:
- I keep forgetting new words! I memorize them first but then can’t recollect them several days later. How often do I need to review them in order to retain them?
Spoiler: to retain new words, you need to review them
- several times
- with certain intervals.
Now more details.
You know that we have a long-term and a short-term memory.
In order to bring a new word to your long-term memory, your brain does it in 2-steps:
- Step 1: It needs to be added to your short term memory first.
- Step 2: It needs to be moved from the short-term to the long-term memory.
The first step is extremely important, and I will write a separate post about HOW to do easily it without outdated cramming.
But now we’ll talk about a Step 2 – retention.
And we’ll talk not about HOW but WHEN.
German scientist Hermann Ebbinghaus researched what happens with our brain if we don’t take special retaining steps when we memorized mindlessly (cramming without building any strong associations for the new words). i.e. what’s happening in the worst case scenario with our memory.
We forget (you know that!).
And we do it pretty quickly (you may be surprise how quickly).
The biggest lost is happening within the first hours.
- in the first 6 hours we tend to retain only 40% of new information (we lose 60%!)
- In 10 hours we lose another 5 % so we retain 35%
- In 6 days we lose another 15% so we retain 20%, and this amount remains the same for months.
It is what is called the forgetting curve, i.e. the decline of memory retention in time IF there was not special attempts to retain it.
So, in order to retain new words (i.e. to help them be moved to the long-term memory easier), we need to review them (which is called active recall) in certain intervals of time.
There are several spaced repetition models – depends on for how long would you like to keep new information in your long-term memory.
With the new words that we learn, we usually would like to keep them forever.
For retaining forever information, here is how it is recommended to use/ review:
- Within the 1st hour: Use a new word minimum 6 times – first time, in 5 sec, in 25 sec, in 2 min, in 10 min, in 60 min.
- 1st review: in 5 hours
- 2nd review: in 1 day
- 3d review: in 5 days
- 4th review: in 25 days
- 5th review: in 4 months
- 6th review: in 2 years.
You can see on the picture how much more you can retain with this method.
Ebbinghaus also discovered the so called edge effect (закон края): we tend to recall the first and last items in a series best, and the middle items worst.
There are many spaced repetition apps that use this effect with their digital cards: Quizlet, Anki, Memrise, Brainscape, etc.
You can enter your new words there and they will help you to memorize new words faster.
Do you know and/ or use any of these apps?
Do you use a system of reviewing new words?