Lexxica provides resources to determine how much vocabulary a student knows and find gaps in their knowledge. They also claim to be able to accurately assess which words a student already knows.
The site is difficult to navigate and prone to crash. If all goes well, try the V-Check to find out how vocabulary you know (works for native speakers, too) and V-Admin to process your data. There are also flash games, free graded texts and flash cards.
I would be interested if other members here tried it and posted comments.
Lexxica: URL - http://www.lexxica.com/
Categories: Text Analysis