What it means to master a word

(and how WordBrewery measures it)

One of the fun design decisions that educational app creators get to make is how to measure​ knowledge. There are people who study the field​ of psychometrics for a living. But we get to explore it a bit as well in order to track learners’ knowledge of the words they find in the news sentences on WordBrewery.

Core principle: results matter—not effort.

Some language-learning apps provide an illusory sense of progress. Completing a particular set of lessons feels good, but it only matters if it meaningfully increases your ability to communicate in your target language. We think it is much less important to measure learners’ effort than it is to measure the learning that resulted from that effort.

In fact, we believe in efficiency, not effort. If you can learn more Spanish, French, or German vocabulary in an efficient 30-minute study session than in an inefficient 60-minute session, you win twice: once by saving time and energy, and again by learning more than you would otherwise.

In short, the meaningful metric is not how many lessons you complete; rather, it is what you can do with your new vocabulary and grammar knowledge and increased reading comprehension.

What we mean by “mastery”

Imagine a book.

When you read that sentence, did you have to pause to think about the definition of “book”? No; in fact, you may have immediately began to follow the sentence’s direction by picturing a book in your mind. You probably didn’t have to think about the words in that sentence at all.

That is what it means to be fluent, and that is what it feels like to have mastered a word. When you understand and process a word’s meaning without effort or delay—without even noticing it—you have mastered the word.

The only way to master a word is by seeing it and comprehending it in many different contexts. Memorizing the word’s definition has little to do with it: remember, you didn’t have to pause to think of the definition of “book” when I asked you to imagine a book. When you learned the words “mama” or “daddy” or “doggy” at age two, no one brought you a dictionary to assist you. You simply learned to associate those words with their meanings.

So when we designed WordBrewery’s system for tracking your mastery of a word, we tried to ensure that your statistics only count a word as mastered if you have in fact mastered it—if it is firmly embedded in your long-term memory, and if, when you encounter that word in your target language, you will not have to pause or stumble over it. The word will be yours.

The details: how WordBrewery tracks your vocabulary knowledge

  • You have a Knowledge Score of 0-100 for each of the 30,000 most common words in your target language.

  • Every time you interact with a sentence in either Course Mode or Explore Mode, your knowledge score changes for each word in the sentence. For example, clicking a word to see its meaning slightly lowers your score for the word; continuing to another sentence without clicking the word slightly increases your score for that word.

  • Answering quiz questions in Course Mode also affects your knowledge score for each word in the sentence serving as the quiz prompt and, in multiple choice questions, for each word presented as an answer choice. Skipping a quiz question has no effect on your knowledge statistics.

  • We use the following labels to describe different levels of word knowledge on the path to mastering the word:

Knowledge Score Label Description
0 New A word you have never seen on WordBrewery.
1-20 Nearly New A word you have seen on WordBrewery, but probably need to practice.
21-59 Familiar A word you probably know, but should review occasionally to solidify your long-term memory.
60-89 Learned A word you know well, but possibly less well than a word in your native language.
90-100 Mastered A word in your long-term memory that you can recognize and recall fluently as though it were a word in your native language.

A WordBrewery course continues until you have mastered all of the 500 target words taught in the course

  • The purpose of a course is to master all of the target words of the course by studying them in the context of many different sentences selected specifically for you according to your current word knowledge. You can read more about Course Mode here, and you can browse our currently available courses here. We currently have Accelerated Beginner and Intermediate courses available for Spanish, English, and German; French will be added in the next few days. Please send us a tweet (@WordBrewery) or email us with your requests and feedback.


We put a lot of time and research into developing our word knowledge scoring system. We think the level of “Mastery,” reflected in your “Words Mastered” counter, represents true mastery of a word rather than just “points” or some other internal measure. This is because, on WordBrewery, there is no way to demonstrate knowledge of a word unless you’ve seen many real examples of the word in different sentences. In the progress of all of that reading, if you have not recently had to look up the word by clicking it, there is a good chance that you have thoroughly internalized its meaning and can now read it fluently.

The Course Dashboard for WordBrewery's Intermediate Spanish course By the end of WordBrewery’s Intermediate Spanish course, this learner will have thoroughly mastered the 1,000 most common word families in Spanish and will understand about 90% of the words they encounter in daily life.