It's a teaching device. I think it would be more helpful with a corrections section but I'm sure that people would just cheat. Whatever the case may be, I'm done with it for the semester. Yay.
It's decent...so so...when it comes to language textbooks. It provides a lot of information. However, I feel that it does not integrate enough information on its own. It works great as a tool in a classroom, but is hindered when teachers fail to elaborate on a topic that students do not know needs elaborated.