Cliff Notes

CliffsNotes (formerly Cliffs Notes, originally Cliff's Notes and often, erroneously, CliffNotes) are a series of student study guides available primarily in the United States. The guides present and explain literary and other works in pamphlet form or online. Detractors of the study guides claim they let students bypass reading the assigned literature. The company claims to promote the reading of the original work, and does not view the study guides as a substitute for that reading.

CliffsNotes was started by a Nebraska native named Clifton Hillegass in 1958. He was working at Nebraska Book Company of Lincoln, Nebraska, when he met Jack Cole, the co-owner of Coles, a Toronto book business. Coles was also the publisher of a series of Canadian study guides called Coles Notes.

Hillegass and his wife started the business in their basement at 511 Eastridge Drive in Lincoln, with sixteen William Shakespeare titles. CliffsNotes now exist on hundreds of works. The term "Cliff's Notes" has now become a proprietary eponym for similar products.

IDG Books purchased CliffsNotes in 1998. John Wiley & Sons acquired IDG Books (renamed Hungry Minds) in 2001. In 2011, CliffsNotes announced a joint venture with AOL and reality TV show producer Mark Burnett to introduce a series of 60-second video study guide surveys of literary works. CliffsNotes was acquired by Houghton Mifflin Harcourt in 2012, and—according to the site's "About" page—"the brand lives on today as part of the global learning company, and its mission of changing lives by fostering passionate, curious learners."

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