The challenge-based learning framework emerged from the "Apple Classrooms of Tomorrow—Today" (ACOT2) project initiated in 2008 by Apple, Inc. to identify the essential design principles of a 21st-century learning environment (Apple Inc., 2008). Starting with the ACOT2 design principles, a team from Apple, Inc. worked with exemplary educators to develop, test and implement challenge-based learning.
The initial framework was documented in a white paper written in 2008 and published by Apple, Inc (Nichols and Cator, 2009). Since that time teachers and schools around the world have adopted the framework to improve teaching and learning while allowing students to make an immediate difference in their community.
In 2009 New Media Consortium published an in-depth study of challenge-based learning in classroom practice. The study, which involved 6 schools in the United States, 29 teachers, and 330 students in 17 disciplines, found the approach produced dramatically effective results, especially for the 9th-grade students considered to be most at risk of dropping out (Johnson, et. al., 2009).
In 2011 an additional study was conducted to test if the framework applied to a larger K-20 audience and to look deeper into the acquisition of 21st century skills. This study includes 19 schools, 90 teachers and 1500 students from three countries. Once again the research demonstrated that CBL is an effective way to engage students, meet curriculum standards, and gain 21st-century skills. The research also concluded that CBL could be used with students of all ages (Johnson and Adams, 2011).
# Recent Developments
In 2016 Apple Inc. engaged Digital Promise, and members of the team that created CBL to update the content, manage the website and develop a book (Nichols, et. al., 2016).
The CBL framework has been extended into new areas including strategic planning, workplace training (O'Mahony, et. al., 2012), and mobile software instruction and development (Santos, et. al., 2015).