Japanese Vocabulary: Drilling and Acquisition

The goal of drilling

The goal of drilling is to familiarize yourself with words, not to master the words or even attain reliable, conscious recall of the words.

How much time should you spend drilling each day?

Drilling should generally take no more than 20 or 30 minutes per day. Any more time drilling has greatly diminishing effectiveness (due to mental fatigue) and crowds out other forms of language practice that should have higer priority (listening, reading, and speaking).

How much should you drill an individual word?

Because the goal of drilling is merely to familiarize yourself with words rather than master them, you should only drill an individual word several times before removing it from your pool, regardless of how well you have learned the word. (If you later reencounter the word, you may re-add it to your pool if you think it worth the additional effort.)

Which words should you add to your pool?

For the first few months of learning, it makes sense to add words to your pool from lists of the most commonly used words. However, once you’re comfortable with the top 500 or 1000 frequently occuring words, you should avoid drilling words from lists. Instead, you should focus on words that you organically encounter in listening and reading.

Maintaining the word pool at a target size

If your word pool has too few words, then random selection will pick the same words too frequently. If your word pool has too many words, then random selection will not pick an individual word frequently enough. Thus it’s important to maintain the pool at a certain size. How large exactly? Assuming you drill 100 unique words each day, then a pool size of 300 means that each individual word in your pool will be drilled, on average, once very three days, which is about the right pace.

So for individual words to show up in your drills every, say, three or four days, your pool size should be three or four times the number of words that you drill per day. These numbers determine how many words will typically be removed from your pool per day, which then tells you how many words you should add to maintain the pool at the target size. E.g. if 20 words are removed per day, then you should add 20 words per day (unless, of course, you are far above or below the target size for whatever reason, in which case you should adjust accordingly).

Run the numbers

For reference, if you drill 30 minutes a day, spending 10 seconds on each word, that gives you enough time to drill 180 words. If you want individual words to show up in your drills once every 3 days, then you need a pool of 540 words. If each word is removed from your pool after 7 drills, that means that, on average, 25.7 words will be removed from your pool (because 180 / 7 == 25.7), and so you must add 25.7 words each day to maintain a pool of 540 words. (Or another way to calculate it: words will typically remain in your pool for 21 days, so you need to add enough words to replace your full pool every 21 days, and 540 / 21 is also 25.7.)

Because finding words to add is its own burden on top of the actual drilling, it’s important to get this balance right. My personal preference is:

• target drills per word = 7
• target size of pool = 300
• unique words drilled per day = 100
• words added to pool per day = ~14

This means I spend about 15 minutes drilling each day, and as long as I also do enough reading or listening per day, it’s easy to collect sufficient new words without much extra effort. On days where I have extra time or feel extra motivated, I’ll drill the same set of 100 words twice (spaced several hours apart). The second pass tends to go faster, so this is generally less than 10 extra minutes.

Is this a fast or slow way to learn Japanese?

If I’m typically adding and removing 14 words per day, that means I’m covering about 420 words per month and 2880 per year. Over 4 years (the commonly expected amount of time for learning Japanese to a decent level), this adds up to 11,520 words drilled. So is this rate slow or fast?

Well, on the one hand, covering nearly 12,000 words represents a good chunk of any language, especially if you focus on the words that most frequently occur across the whole language and words from the domains that matter most to you (e.g. baseball terminology if you care about baseball). On the other hand, a typical adult native Japanese speaker’s vocabulary is estimated to be around 40,000 words (though the question of what properly constitutes a unique, individual word is messier in Japanese than in English). Also, recall that this drilling process is merely meant to familiarize ourselves with the words, and we’re very unlikely to fully learn most of the words we drill after just several exposures. However:

1. Drilling is just a supplement for the essential forms of practice: reading, listening, and speaking. If you devote sufficient time and effort into these activities, you will master many vocabulary and kanji through naturally reoccuring, meaningful encounters, assisted by the base level of familiarity you attain through drilling.
2. Vocabulary in every language, including Japanese, is not just a set of independent, arbitrary mappings of sign to signified (though it definitely seems that way in the early stages of learning). As you advance, you will fined that knowledge and mastery of many words help reinforce and unlock other words in the language, thanks to common patterns of word formation and reuse of common elements (e.g. prefixes and suffixes). Effectively, once you have a base vocabulary, it becomes easier to organically acquire an intermediate vocabulary, which in turn helps you organically acquire an advanced vocabulary.

So yes, acquiring just a loose familiarity with fewer than 12,000 words over 4 years would not be a great end result. In practice, though, drilling can help you achieve far more than this as long as you use drilling as just a supplement to the core forms of language practice.

The drilling process

Once a set of words is randomly selected from the pool for a drill session, the drilling process proceeds in rounds:

• For the first round, randomly select ~10 to ~20 words from the set.
• For each word, say the answer aloud or internally, then check the answer. If your answer was right, you remove the word from the set. If your answer was wrong, you include the word in the next round.
• Each subsequent round, include the wrong-answered words from the prior round and then randomly select more words from the remaining set to fill out the round (up to a max of ~10 to ~20).
• The drilling ends when all words have been removed from the set.

Once a word is correctly answered and removed from the set, the word’s lifetime drill count should be incremented, and if the word hits the max drill count target, it should be removed from the word pool.

Note

It’s fine and arguably beneficial if each round sorts all of the wrong-answered words to the front of the list: this allows you to focus a bit more on the words giving you trouble before dealing with the words that are new that round. Also note that the size of each round effects how frequently the wrong-answered words reoccur in between new words: the fewer words per round, the smaller the ratio of new words relative to wrong-answered words carried over from the prior round, and thus you might be less distracted by new words in between repetitions of the wrong-answered words.