The opposite of the Art Institute of Chicago, Intuit houses art created by people that have not had any apparent art training or mentoring from the art world -- hence the term "outsider art." For instance, a recent exhibition featured the art of Lee Godie, a homeless woman who used to sell her paintings and drawings on the streets of Chicago. The Intuit has also recreated the Lincoln Park live/work space of Henry Darger, who worked his life as a janitor but was discovered posthumously to have written a fascinating 15,000 page manuscript highlighted by tons of his drawings and watercolors.
While it might seem that viewing the work of "amateurs" would be futile, most of the art is complex and offers, in my opinion, more of an in-depth look into the artists' mind.
For a decidedly more educated opinion than mine, read about outsider art from About.com's painting expert.
