Crowd-sourcing is one of those modern-day terms with many definitions, but typically people use it to refer to efforts organized online that attempt to draw contributions of free labor from a large number of people. When crowd-sourcing works best, there is a real feeling of community achievement. When it falls apart, it usually looks like a half-baked effort to exploit poorly trained volunteers.
Digital humanist Rebecca Frost Davis has a really good post about the challenges of attempting to use crowd-sourcing in the classroom that everybody in this particular seminar should read carefully. But students should also find the time to look over a couple of pieces from the New York Times that have detailed some of the more notable recent efforts at crowd-sourcing in the corporate world, especially related to open source or open innovation projects. See this first piece from 2009 and then check out this column from 2011 that explores some ways that non-profits have been attempting both crowd-sourcing and crowd-funding endeavors.
Finally, there is a quirky but fun piece from The Atlantic which reminds us that calling for volunteers is something that most definitely predates the Internet. If time allows, also try to read this recent piece from summer 2014 that details how the New York Times once attempted (unsuccessfully) to update its motto with help from the admiring crowd.