Joel A. Michael Allen A. Rovick Michael Glass Yujian Zhou Martha W. Evens Learning from a Computer Tutor with Natural Language Capabilities. 233-262 2003 11 Interact. Learn. Environ. 3 https://doi.org/10.1076/ilee.11.3.233.16543 db/journals/ile/ile11.html#MichaelRGZE03