
About the Vocabulary Size Test
Bruce Zhang (01/22/2004)
Test Results Users take about 10  30 minutes to complete the test. The average time to complete the test is about 15 minutes. The accuracy of the test in the following table is based on feedback from over 800 users.
I was surprised by the percentage of underestimate since the development of the test is very scientific. I can adjust the calculation of the size to increase the accuracy level, but I decided not to. This is a test for estimating vocabulary size under 10,000. Many users who completed the test have vocabulary size way over 20,000. Excluding the users whose estimated size is 8,500 or higher, the adjusted accuracy level is about 60%. Development of the Vocabulary Size Test While thinking of a simple, easy to use, yet scientific way to estimate a person's vocabulary size, I knew it's more of a mathematical problem than a language problem. It is really a very simple statistical sampling in theory. The challenge lays in the implementation. Luck enough, the resources on the Internet have made it possible. The test was developed in the following steps:


