Spaced repetition
Spaced repetition (間隔反復, かんかくはんぷく) is a learning technique where review sessions are scheduled at increasing intervals to exploit the psychological spacing effect. It is widely used for memorizing Japanese kanji and vocabulary, often through flashcard software.
How Spaced Repetition Works
Spaced repetition is based on the observation that humans forget information at an exponential rate unless it is reviewed. The technique schedules reviews just before you are likely to forget an item, which strengthens memory and reduces the total number of reviews needed. For example, you might review a new kanji after one day, then three days, then a week, then a month. Each successful recall extends the interval, while failed recalls shorten it.
The underlying principle is the spacing effect, a well-documented phenomenon where information is better remembered if study sessions are spread out over time rather than massed together. Spaced repetition systems (SRS) automate the scheduling, often using algorithms that track your performance on each item.
Application to Kanji and Vocabulary
For kanji, spaced repetition is particularly effective because each character has multiple components: meaning, reading, and stroke order. An SRS can present kanji in isolation or in the context of words, helping you build associations. For vocabulary, spaced repetition helps you retain the reading and meaning of words, and it can be combined with example sentences to reinforce usage.
Many learners use pre-made decks or create their own. The key is to keep reviews short and frequent, and to focus on items you find difficult. Some systems allow you to add mnemonics or images to aid memory.
Where It Fails
Spaced repetition is not a magic bullet. It fails when:
- You review without context: Memorizing isolated kanji or words without seeing them in sentences can lead to shallow knowledge. You may recognize the character but not know how to use it.
- You ignore production: Most SRS focus on recognition (seeing the kanji and recalling the meaning). You also need to practice writing and recalling the reading from the meaning, which some systems support but others do not.
- You over-rely on the algorithm: The algorithm schedules reviews based on your responses, but if you are not honest with yourself (e.g., pressing "easy" too often), the intervals become too long and you forget.
- You lack motivation: Spaced repetition requires consistent daily practice. If you skip reviews for a week, the backlog can be overwhelming, and you may give up.
- You use it for grammar: Spaced repetition is not well-suited for learning grammar patterns, which require understanding and production in context. Grammar is better learned through input and practice.
Practical Tips
- Use a reliable SRS: Popular options include Anki, Memrise, and WaniKani. Each has its own algorithm and features.
- Create your own decks: Pre-made decks may not match your learning goals. Adding your own example sentences and mnemonics can improve retention.
- Combine with other methods: Use spaced repetition alongside reading, listening, and speaking practice. The goal is to encounter the language in real contexts.
- Set a daily limit: To avoid burnout, limit new cards per day (e.g., 10-20) and keep review sessions under 30 minutes.
Limitations and Misconceptions
Spaced repetition is often marketed as a "scientific" way to learn, but it is only one tool. It does not guarantee fluency, and it cannot replace meaningful interaction with the language. Some learners expect to memorize thousands of kanji in a few months, but retention requires time and practice.
A common misconception is that spaced repetition is the same as rote memorization. In fact, it is a scheduling technique that can be used with any learning method, including context-rich learning.
Related Resources
Spaced repetition is often mistaken for a method of memorization, but it is actually a scheduling technique that can be applied to any learning material.
Questions
How often should I review with spaced repetition?
The intervals are determined by the algorithm, but typically you review new items within a day, then after a few days, then a week, and so on. The exact schedule depends on your performance.
Can spaced repetition help me learn kanji faster?
It can help you retain kanji more efficiently, but it does not speed up the initial learning. You still need to study each kanji, and the intervals are designed to optimize memory, not to cram.
Is spaced repetition better than traditional study methods?
It is more efficient for memorization because it reduces the time spent on items you already know. However, it is not a substitute for comprehensive study that includes reading, writing, and speaking.