We forget 90% of what is taught in class within 30 days.
Over a hundred years ago the German psychologist Hermann Ebbinghaus (1885) came to this conclusion after painstakingly exposing his human subjects to list of words. He also discovered that most of this forgetting occurs just hours after being exposed to the new material. It is called the curve of forgetting.
When we encounter new information, neurons in our brain activate, but the stimulation lasts only up to 90 minutes unless it is reactivated (Squire, Kandel, 1999). We begin to commit the new learning to memory when we first practice it, but for learning to endure in our memory, we must return to it at intervals and in different ways over weeks, months, and even years.
A popular model in education is “teaching to mastery”. We often interpret this to mean that students need to practice a language point intensely until it is burned into memory. Indeed, while students are practicing, they demonstrate an easy fluency with the material. That is because it is active in their working memory. Teachers and students alike prefer this intensive kind practice because it produces rapid, if ephemeral, gains. Quickly students gain confidence in their control of the material. It feels familiar and known. If tested immediately after intensive repetition and in a way that simulates the rehearsal, students score well.
It turns out, however, that intensive repetitive practice leads to quick learning AND quick forgetting. (Dunloskey, 2013). If students are tested on that same material just a day later, their scores drop precipitously. The challenge is to have students put the material aside and then return to it. Inevitably they will have forgetten some of the material, and that is ok. The effort they make to retrieve and reconstruct the information each time they practice it anew will strengthen their memory.
Interval Learning = Long-Term Learning
Practicing material at intervals over time is more effective than practicing material intensively in a short period of time. (Cepada 2003.) Students who practice at intervals retain their knowledge and skills for a longer period than those who practice it intensely all at once, even when controlled for total time spent practicing the material (Dunloskey 2013). This means one hour of intensive practice is less valuable than four intervals of 15 minutes each.
Intervals can be as short as five minutes, or twenty-five minutes. This way you can get students retrieving something they practiced a couple of activities prior in the class. But then ideally the intervals should occur at longer and longer lag times over the ensuing days, weeks, and months. Between each interval, students begin forgetting the information. Then, when students make an effort to retrieve that information, they strengthen their memory of their learning.
Built-in Reviews: Class Warm-Up
At the beginning of class, ask students what they learned in the last class.
Have students briefly identify the material studied in textbook and notes to update any previously absent students.
Built-in Reviews: Class Recap
At the end of class, ask students to tell you what they learned in class. This may be the first time they are returning to a topic.
Student Organization: Study Calendars
- Hand out weekly calendars or have students use their cell-phone calendars.
- On the first class of the week, ask students to schedule at least four times they will study English outside of class.
Student Organization: Data Speaks
- At the start of each week, ask students to look at their calendar and to count the number of times they studied English outside of class the previous week.
- Then test student retention of the material presented and practiced in the previous week. To test, you can use a section of your textbook’s unit test, or a simple dictation of questions or prompts to which students write responses.
- At the top of the test, have students write the number of times they studied the previous week. Quickly, students will recognize the relationship between studying at intervals and their retention of knowledge and skills.
Simple and challenging assessments are essential to developing memory of learning. Make sure you do these regularly and recycle previously learned material.
Dictation: Site the Setting
- Dictate two lines from a conversation students learned in previous lessons.
- Have students identify who the speakers are and where they are talking. For example:
A: May I help you?
B: Yes, I’d like a coffee and a sandwich.
Who: An employee and a customer.
Where: A restaurant.
Dictation: Quick Quiz
Dictate questions that ask students to recall previous learning. For example:
What are three kinds of over the counter medicine?
How many colors do you see in the classroom?
What are the four seasons of the year?
What occupations are in restaurant work?
Dictation: Word Works
- Keeping a running list of words students are studying.
- Dictate recently learned words to test spelling. Every time add a few words from previous units.
Correct the Errors
- Write common errors into sentences on cards- one per card.
- Distribute the cards. In pairs student find the error and write the sentence correctly on a piece of paper.
- Check their work. If correct provide the pair with a new error on a card.
A Thousand Words
- Project an image that contains items students have learned in previous classes.
- Give pairs of student 3 minutes to generate as many words as they can.
- Review the lists together.