Back in March 2011, I wrote a web application to estimate how many Chinese words a person knows. The test works similar to a flashcard set: for each word presented, you mark whether you know the word (using your own judgment), optionally revealing the pinyin and English definition before deciding. A sample of 165 words is drawn from the top 36,000 in the Lancaster Corpus of Mandarin Chinese. At the end, the results are extrapolated across frequency bands to give an estimated vocabulary size. A Chinese character test was added later, with the same methodology, but at the character level rather than the word level. The app has been quietly running for 15 years now.
The app now has a new test – Vietnamese! It’s been something I’ve wanted to add since starting my Vietnamese studies last year, to get an estimate of my progress at various points. The test follows the same format as the Chinese ones – a sample of words drawn from a frequency list, marked known or unknown, with a vocabulary estimate at the end. Before the main test, there is a short pre-test with a few questions to gather some anonymous information about your current level of Vietnamese. This data will be used for future analysis, similar to the original research motivation behind the Chinese test. If you are a Vietnamese learner at any level, give it at try! The tests are all at https://www.zhtoolkit.com/apps/wordtest/.