"You can always watch your progress, thanks to the progress bar sitting right on your screen, and every challenge you encounter comes with a ranking and color-code. If a quest is too difficult, it's marked red, or it's not even offered to you; if a monster is much weaker, its level shows up in gray. Instead of letting you think you should take a wild swing and see if you get lucky, the game reinforces that you should tackle a challenge that's right at your level.
Gamers feel the most sense of accomplishment when they're always facing just enough of a challenge - as described by Mihaly Csikszentmihalyi's concept of 'flow.' You can credit World of Warcraft's addictiveness to how well it paces those challenges - and plenty of smart educational technologists beat and tinker with assessment algorithms, trying to accomplish the same thing. So, what if a game like World of Warcraft could be built around educational content - say, instead of killing murlocs, you're solving math problems?" In "Playing to the Test," Chris Dahlen explores the nature of educational games, and how they may be just what the educational system needs.