Thinkmap, the company behind the Visual Thesaurus, has just launched Vocabulary.com, a free tool for assessing which words students need to learn and in giving them the motivation and means to master those words.

Visitors to Vocabulary.com can join The Challenge, answering vocabulary questions designed to evaluate and teach vocabulary words.

Adaptive Vocabulary Instruction (AVI), provides the right question at the right time, regardless of proficiency level, while the Dictionary uses predictive technology to display the appropriate definition before the user has finished typing the word.